17-21 June 2019
IMLAUER HOTEL PITTER SALZBURG
Europe/Vienna timezone
Deadline Full Paper Submission - 15 November 2018 (Paper Limitation - 6 pages)
Home > Contribution List

Contribution List

Displaying 238 contributions out of 238
Multiple dendritic equiaxed grain formation is common to solidification in many technical alloys in industrial solidification processes. We investigate this type of grain formation and competition during directional solidification of grain-refined Al-3.5wt.-%Ni at various solidification conditions by comparison of experimental data and 3D dendrite needle network (DNN) modeling. For the experiments ... More
Presented by Dr. Laszlo STURZ
The microstructure formed during the solidification processing from the melt is a critical issue for industrial applications. Most of the mechanical properties of alloys are a result of these microstructures. Understanding and predicting both the microstructure formation and evolution are crucial for the development of performant materials. Since microstructures are strongly influenced by the hist ... More
Presented by Dr. Fatima MOTA
A 3D meso-scale discrete-element model has been developed to simulate fluid flow during dendritic solidification of a binary Fe-C alloy. The model domain is a representative volume element consisting of hundreds of equiaxed dendrites along with corresponding liquid channels, where the final grain shape is given by a modified Voronoi diagram. Solidification of each dendrite is simulated via an aver ... More
Presented by Ms. Yi FENG
The last decade has witnessed the development of various solidification models based on volume averaging methods. To reduce the calculations cost, the averaging reduces information contained within the mushy zone to a single variable, the solid volume fraction. The solidification rate and the permeability are then calculated with the help of closure laws often based on some semi-empirical correlat ... More
Presented by Prof. abdellah KHARICHA
A mathematical model has been established to coupling predict the formation of inverse segregation and porosity for up-vertical unidirectional solidification of Al-Cu alloys. Based on the analysis on the redistribution behaviours of both gas element and the alloying elements in the mushy zone. The model first investigates the volume change during solidification intensively, including the specific ... More
Presented by Prof. Wanqi JIE
Previous studies have shown that it is extremely problematic to add synthetic inclusions successfully into liquid steel for clean steel experiments. Small micro-particles encapsulated in a metallic parcel are difficult to pass through the melt-gas interface and inclusions tend to agglomerate then float up to the liquid surface. In this study, powder metallurgy is used to distribute cerium oxide ... More
Presented by Mr. Andrew SMITH, Dr. Tu TRAN
In phase field modelling of solidification, one always assumes a smooth, symmetric, change between solid and liquid across the interface region in near equilibrium 1D solutions. Such a construction is usually motivated by computational convenience, and this is reflected by computational modelling where the gradient employed in the liquid-solid interface is much lower than realistic. To obtain qu ... More
Presented by Dr. peter BOLLADA
The manufacturing of special steel forgings normally follows the basic technical process from casting, homogenization annealing, pre-heating, forging and post-heat treatment after forging. Such treatment obviouly is high-cost, energy dissipation and long manufacturing cycle. In terms of the formation mechanism of internal casting defects such as macrosegregation, shrinkage cavity and coarse grains ... More
Presented by Dr. Yanfei CAO
The paper presents a partitioned resolution algorithm for concurrent simulation of fluid flow and solid mechanics with application to solidification processes. The general objective is to concurrently model liquid flow in the non-solidified regions and solid deformation in solidified regions. The scheme is developed to include partially solidified regions (i.e. mushy zone) as this is the locus for ... More
Presented by Mr. SHAOJIE ZHANG
Abstract: The existence of local areas of high nitrogen concentration in titanium is highly problematic as they pose a risk of causing fatigue failure in aero-engine disc material. The particles responsible for these areas can come from various sources and can range in composition from a few weight percent up and including non-stoichiometric TiN particles. The challenge in removing these particles ... More
Presented by Prof. Steven COCKCROFT
In modern automotive structural components, metal sheets are combined with casting parts to enable a light and mechanical stable structure. In this study, the bonding between steel metal sheets and aluminum casting parts are achieved as part of the high pressure die casting (HPDC) process. In this way additional bonding steps like welding can be omitted. Gas enclosure at the interface between m ... More
Presented by Dr. Juergen JAKUMEIT
IDS (InterDendritic Solidification) is a thermodynamic-kinetic software package, which simulates phase changes, compound formation/dissolution and solute distribution during solidification of steels and during their cooling/heating process after solidification. The software package also simulates solid state phase transformations related to the austenite decomposition process (ADC module), at temp ... More
Presented by Dr. Ville-Valtteri VISURI
In recent years, the automotive industry has been increasing the production of small, high-power gas engines as part of several strategies to achieve the new “Corporate Average Fuel Economy” (CAFE) standards. This trend requires an improvement in the thermal and mechanical fatigue durability of the aluminium alloys used in the production of the engine blocks. Conventionally, solid chills are e ... More
Presented by Dr. Farzaneh FARHANG MEHR
Compacted graphite iron (CGI) is used in various complex automotive components due to its suitable combination of physical and mechanical properties. This study aims to investigate the solidification of CGI by employing a newly developed experimental technique. 400g specimens of spheroidal graphite iron are remelted in an Argon atmosphere and subsequently solidified as CGI by controlling the expos ... More
Presented by Björn DOMEIJ
The quantitative prediction of dendrite fragmentation has remained a major issue in the modeling of solidification processes. A systematic approach to this issue is presented that consists of two parts. First, a thorough analysis is carried out of existing and new experimental data. A suite of different image processing techniques is developed that allows for obtaining robust statistics of the com ... More
Presented by Dr. Hieram NEUMANN-HEYME
Correct prediction of composition heterogeneities and grain structure across a steel ingot is critical in optimizing the industrial processing parameters for enhanced performance. Previous studies using the SOLID® software have been able to predict the grain structure, grain density, grain morphology and macrosegregation pattern in industrial scale ingots by incorporating fragmentation and hetero ... More
Presented by Mr. Savya SACHI
Macrosegregation refers to the inhomogeneous distribution of alloy elements at the macro scale in solidified castings. It is a common defect in direct chill (DC) casting of aluminium alloys. Since various transport phenomena contribute to the formation of macrosegregation, numerical modelling is a valuable tool to assess their role and study their interplay with process parameters. One such parame ... More
Presented by Dr. Mohammed M'HAMDI
We present an in situ experimental study of crystallographic effects during lamellar- eutectic growth in thin Al-Al2Cu samples. The Al-Al2Cu alloy is known to form eutectic-grain dependent lamellar eutectic microstructures, and to present special, or heteroepitaxy orientation relationships (OR) between the eutectic crystals. The term crystallographic effects refers here to a marked dependence of t ... More
Presented by Dr. Sabine BOTTIN-ROUSSEAU
We have used a concentric solidification technique to study events occurring in the early stages of solidification during the continuous casting of steel. We have found that the major factors contributing to crack susceptibility are the fraction of δ-phase present prior to the occurrence of the peritectic reaction; the rate at which the δ-to-γ interface propagates and the extent of undercoolin ... More
Presented by Prof. Rian DIPPENAAR
The applicability of the classical heterogeneous nucleation theory for an inoculated Al-18.6Si (wt%) alloy was investigated. In this work, nucleation models (surface-dependant and volume-dependant) proposed by Perepezko were used to study the heterogeneous nucleation of primary silicon in phosphorus-inoculated alloys. For this metallic system, the nucleation temperature was found to be the most cr ... More
Presented by Dr. Masoumeh FARAJI
Due to start-up and shut-down operations of engine, TiAl structural components usually should undergo not only static but also cyclic mechanical loading. The crack propagation mechanisms of γ-TiAl under two types of loading are studied in this work to reveal the differences of the mechanisms under constant strain rate and cyclic loading. Since the crack prefers to nucleate at the interface, two t ... More
Presented by Mr. Li WEN
Type: Poster
To achieve the highest productivity and reach your targets, the plant stoppage should be decreased, the most and monster of any casting process is the breakout under the mold during casting as it causes plant stoppage from 1 hour to 9 hours (according to breakout severity, so analysis, controlling and review the crews’ performance are considered to be some important things to control the breakou ... More
Presented by Mr. Magdy FESHAR TALAAT
Grain boundary grooves (GBGs) are common features on polycrystalline solid-liquid interfaces. Stationary GBGs, of course, support distributions of their Gibbs-Thomson thermo-potentials along their curved interfaces, but, surprisingly, the vector gradients of these potential distributions excite *persistent* capillary-mediated energy fluxes. Moreover, these steady interfacial fluxes exhibit vector ... More
Presented by Prof. Martin GLICKSMAN
Solidification phenomena during laser additive manufacturing (LAM) occur under rapid solidification conditions, with the entire melting and solidification process occurring in a few milli-seconds. New characterisation techniques are required to capture the powder-melting, weld pool formation, together with the subsequent solidification phenomena including defect formation. To enable this, a laser ... More
Presented by Prof. Peter LEE
Recently, Additive manufacturing (AM) has emerged as a disruptive technology to manufacture complex parts with greater scales of economy and also with a reduced need for post-machining. However, the influence of processing conditions and the alloy compositions on the strength, defect formation are not yet fully understood. A quantitative simulation of the microstructure morphologies and segregatio ... More
Presented by Mr. Abhishek G.S.
Investigative efforts aimed at improving the understanding of the microstructural transitions in solidified metallic alloys are requested. Indeed, it is well known that the application properties of the metallic alloys will greatly depend on the final morphology of the microstructure. Determining the ranges of cooling rates associated with dendritic-cellular transition in multicomponent alloys is ... More
Presented by Prof. Crystopher BRITO
This paper demonstrates time-resolved and in-situ tomography using synchrotron radiation X-rays in SPring-8. Voxel size of reconstructed image was approximately 6.5 μm x 6.5μm x 6.5μm and time resolution was 0.5s - 4s (2rps - 0.25rps). Convolution back-projection (CBP) image reconstruction was typically performed using 200 transmission images. The technique was applied to observe dendritic stru ... More
Presented by Prof. Hideyuki YASUDA
Computational process modeling has become an important engineering tool in the casting industry to predict the solidification sequence in complex castings. Used properly, this tool can help reduce manufacturing costs. One of the challenging issues in developing casting simulations for the low pressure die casting (LPDC) of automotive wheels is to quantify the heat transfer coefficients (HTC) withi ... More
Presented by Ms. Anis Umi SAADAH BINTI OTHMAN
Graphite degeneracy in heavy-section spheroidal graphite cast irons is mostly associated with the formation of chunky graphite which consists of large eutectic cells with interconnected graphite strings. At low level, appearance of chunky graphite is limited to its anaesthetic effect on machined surfaces, while at higher level it is detrimental for mechanical properties of the components. Chunky g ... More
Presented by Dr. Jacques LACAZE
The formation of coarse Fe and Mn containing intermetallic particles during the DC casting of Al-Mn-Ti-Fe-Si alloys is detrimental to the alloys' cracking susceptibility, formability and even final mechanical/corrosion properties. In this talk, SEM/TEM are employed to reveal the microstructural features of the particles including composition, size distributions and morphologies. These experimental ... More
Presented by Dr. Qiang DU
The increasing tendency for near net shape production of industrial parts, taking advantage of costs reduction and quality improvement, is turning semi-solid processing into viable technologies. The Strain-Induced Melt Activation (SIMA) and the Rheocasting are the two semi-solid processing routes to produce feedstock with globular microstructure. In this work, the microstructure development in the ... More
Presented by Prof. Vinicius KARLINSKI DE BARCELLOS
Since last century, two and three-phase models are generally adopted for the meso-scale simulations of the growth of equiaxed grains in solidification of binary and ternary alloys [1]-[3]. Yet, as far as three-phase models are concerned, their implementation in the macro-scale model with the equiaxed grains transport can be realised in different ways. Indeed, since the solid fraction of a grain an ... More
Presented by Dr. Olga BUDENKOVA
The understanding of heterogeneous nucleation of intermetallic compounds (IMCs) during solidification of engineering alloys is of both scientific and technological importance, and is particularly relevant to recycling. However, effective refinement of IMCs is currently limited by our poor understanding of their heterogeneous nucleation. In this contribution, we present out latest advance in the un ... More
Presented by Dr. Zhongping QUE
This work aims to provide a comprehensive in-situ observation from solidification to phase transformation in low alloy steels with different grades, and the analyses of their phenomena. 1) Liquid/δ-ferrite, δ-ferrite/γ-austenite interfaces mobility: In-situ kinetics of liquid/δ-ferrite and δ-ferrite/γ-austenite interfaces mobility during solidification and phase transformation are obser ... More
Presented by Dr. Mu WANGZHONG
High-carbon steels used for the production of tire cord have rather simple steel chemistry with carbon being the main alloying element. They are however quite challenging to produce as segregation must be minimized and steel cleanness must be maximized. One technology that is often employed in continuous casting of high-carbon steels to minimize centre- (or macro) segregation is so-called hard sec ... More
Presented by Dr. Anthony Nicholas GRUNDY
An experimental device was developed with a technique to simultaneously evaluate cooling curves and expansion or contraction of cast metals during solidification. It conducts thermal analysis and volume change measurements in a single ceramic cup so that mould media as well as solidification conditions are constants, with cast iron quality as the variable. The recorded data are processed using spe ... More
Presented by Prof. IULIAN RIPOSAN
Type: Poster
As nonmetallic inclusions (NMI) are unavoidable in steel production and commonly have a negative impact on product quality. Metallurgical research has always aimed at either the adjustment of inclusion morphology or inclusion separation to minimize their adverse effects. In the 1990s the conscious nucleation of particles to either promote or inhibit the subsequent growth of other phases became a n ... More
Presented by Prof. Christian BERNHARD
Open Source Phase-Field based Bulk Flow with Solidification Model for Steel Arunava Sengupta*1, Begoña Santillana2, Seetharaman Sridhar3 and Michael Auinger1 1Warwick Manufacturing Group, University of Warwick, Coventry, CV4 7AL, UK 2Tata Steel Research and Development, 1970CA IJmuiden, the Netherlands 3Colorado School of Mines, CO, US *Email: A.Sengupta@warwick.ac.uk Abstract: ... More
Presented by Mr. ARUNAVA SENGUPTA
The columnar growth of Ti-48Al-2Nb-2Cr alloy was investigated using power down directional solidification experiments under various gravity conditions, ranging from micro-gravity to 20 g. The g-vector always pointed in direction opposite to the growth direction. The columnar dendrite morphology and primary spacing was analyzed in longitudinal and transverse sections and for selected experiments in ... More
Presented by Dr. Julien ZOLLINGER
This second paper addresses the phase field modeling of columnar dendritic growth for different scenarios of fluid flow developing in response to gravitational forces. For this the experimental Ti-48Al-2Cr-2Nb alloy has been simplified to a binary alloy Ti-48 at.% Al. The 2D simulations confirm the decrease of the primary dendrite arm spacing with increasing gravity, nearly matching the experiment ... More
Presented by Dr. Alexandre VIARDIN
The main coexisting phases during solidification of lamellar graphite iron, the liquid phase, the precipitating austenite and graphite are interacting and causes a complex volume change pattern. In the present work the density of liquid iron and the austenite phase is investigated based on measurements with a push-rod dilatometer. The values of the densities have been calculated based on the assum ... More
Presented by Prof. Attila DIÓSZEGI
Achieving a high undercooling prior to solidification (△T) is expected to be an effective strategy to significantly reduce lamellar spacing of bulk eutectic alloys which will be of great benefit to either mechanical or functional properties of eutectic alloys. However, the undercooled eutectic alloys usually exhibit coarse anomalous eutectic structure when △T exceeds a critical value. The form ... More
Presented by Prof. Yuzeng CHEN
Controlling of steel cleanliness has always been an issue of great concern for the metallurgists, because the bubbles/inclusions influence directly the mechanical properties of the slab, lead to internal cracks, slivers, and blisters in the final rolled product. Two studies concern inclusion distribution in the slab have been carried out in the current work. First, the three-dimensional inclusio ... More
Presented by Mr. Xiaoming RUAN
In recent years, the development of computational models to predict casting distortions has led to improvements in efficiency and accuracy over traditional pattern design that relies on shrink rules. Unfortunately, the determination of pattern dimensions using simulation remains a trial-and-error process that requires several design iterations. In this study, the finite element inverse deformation ... More
Presented by Dr. Daniel GALLES
The Newtonian Thermal Analysis (**NTA**) is used quite often for analysis of the rate of heat released during the alloys’ solidification. For the estimation of the solidification kinetics the cooling rate (approximated on the base of the temperature measurements) is compared with a base cooling rate diagram determined for the cooling of the same probe without exothermic transformation in the sim ... More
Presented by Prof. Andriy BURBELKO
Analysis of grain structures as formed during directional solidification is of significant interest in the study of directionally solidification and the development of deeper understanding of grain selection. In the case of dendritic microstructures, different grains, as formed during solidification, can usually easily identified by just looking at micrographs from optical or electron microscopy a ... More
Presented by Dr. Nils WARNKEN
The thermal expansion coefficient (α) of ferritic nodular cast iron was measured in a dilatometer. During the work, twelve samples were taken from different cross-sections of a large casting. These samples were machined in the lathe to make round bars with an approximate size of 3 mm diameter by 26 mm length. The effect of cooling rate on α was investigated by using variable rates during the exp ... More
Presented by Dr. Abel TADESSE
The existence of oxide inclusions (e.g. Al2O3) in the steel melt is unavoidable. Most of these nonmetallic inclusions come from the steel-making process. During solidification, some of these inclusions remain in the melt and interact with melt flow and the growing crystals. The movement of solid oxide inclusions in steel melt is directly numerically simulated through coupling the solid particle mo ... More
Presented by Dr. Yun CHEN
The fragmentation of dendrites immediately following the recalescence phase of growth during the solidification of undercooled melts has been invoked to explain various rapid solidification microstructures. Such fragmentation is thought to occur via the growth of a Rayleigh type instability along the dendrite arms. Despite this, little direct evidence of such a fragmentation process usually surviv ... More
Presented by Prof. Andrew MULLIS
Double dendrite growth of an aluminum alloy was observed in directional solidification under certain thermal conditions. However, the underlying mechanisms of double dendrite growth remain unclear. Using the simulation of two-dimensional phase-field implemented on a cluster of parallel computers, double dendrite growth of Al-Cu alloy during the directional solidification was investigated. Using Al ... More
Presented by Mr. Chu HAN
In the present study, effect of cooling rate on the formation of the porosity in the thick aluminum sand casting was investigated. Nowadays large scale thick aluminum casting replaces steel frame for vacuum chamber compartments in the semiconductor factory, with the consideration of weight and cost reduction. Aluminum casting specimens and real large castings were manufactured using chill with tem ... More
Presented by Dr. In-Sung CHO
The remelting behavior of the tempering steel 50CrMo4, was investigated with several experimental melts on a lab-scale ESR-plant. The investigated parameters included a variation of the slag compositions and the use of a protective nitrogen atmosphere. Variations of the slag composition comprised slags with different contents of CaF2, CaO and Al2O3 as well as a variation of the SiO2-content in the ... More
The unidirectional solidification of Al-6Si-4Cu-2Fe alloy was performed in a vertical Bridgman furnace with bottom cooling. The diameter of cylindrical samples was 8 mm and their length was 120 mm. In the course of the experiments, a sample movement velocity of 0.1 mm/s was used and the experiments were performed by applying of RMF magnetic stirrings having different intensities. During the solidi ... More
Presented by Prof. András ROÓSZ
Deleterious effect of sulphur excess in gray iron is shortened by Mn addition. The suitable Mn addition according to sulphur in the metal is preformed according to the different addition rules available in open literature. With Mn addition is intended to avoid FeS formation by MnS precipitation that also prevents the undesirable effect of sulphur dissolved in the melt in the morphology of graphit ... More
Presented by Dr. Manuel de Jesús CASTRO-ROMÁN
Die casting process is widely used in making Al and Mg alloy components, especially in automotive industry. In the process, due to high speed filling of liquid metals gases in die cavity are prone to be entrapped resulting in final pores in the castings. The pores are detrimental to the casting properties and performance. In this study, the pores in die-cast AlSiMgMn alloys were inspected and ... More
Presented by Prof. Haidong ZHAO
The semi-solid processing aimed to modify the solidification morphology, from dendritic to globular structure, turning this process interesting to improve the properties of magnesium alloys. This work aims to analyze the influence of the cooling rate and the stirring time on the microstructure of the MRI230D alloy submitted to the rheocasting process. The material was processed in the semi-solid ... More
Presented by Prof. Bartex LUIZ TELLES BARTEX
Ti-Al alloys have been studied for more than 20 years due to their low density and high resistance in high temperature environments, making them a good candidate for automotive and aerospace applications. However, their high reactivity in liquid state makes them difficult to cast because they need to be cast at very low superheat and at fast filling rates. Centrifugal casting enhances the mold fil ... More
Presented by Mr. Martín Matías CISTERNAS FERNÁNDEZ
We present an experimental investigation on the effects of the interphase energy anisotropy on the formation of three-phase growth microstructures during directional solidification (DS) of the β(In)–In2Bi–γ(Sn) ternary-eutectic system. Standard DS and rotating directional solidification (RDS) were performed using thin alloy samples with real-time observation. We identified two main types ... More
Presented by Dr. Samira MOHAGHEGHI
The alloy casting process is one of the major manufacturing processes to produce near net shape components. The casing process is prone to a wide variety of defects, with hot tear being one of the most detrimental. The two main factors generally recognized as the primary cause for formation of hot tears are the mechanical response of the mush (which effects its permeability), and the solidificatio ... More
Presented by Mr. Shishira BHAGAVATH
An efficient model for the prediction of dendritic grain growth is developed coupling the lattice Boltzmann method for solving the transport of solute and a cellular automaton algorithm for determining the evolution of grains' envelope and the release of solute during phase change. In contrast to solving equations from the field of continuum mechanics the new model is more related to particular oc ... More
Presented by Mr. Stephan JÄGER
Electromagnetic effect produced in alloy melt and dendrite growth under the action of a pulsed magnetic field are researched by experimental and simulation. Simulation results show that alternating gradient electromagnetic forces act on the melt in front of the interface of the growing dendrites and the maximum electromagnetic force appears near the front of the solid/liquid interface, which forms ... More
Presented by Prof. Yuansheng YANG
Grain refinement of aluminium alloys has always been desirable in foundries. It is a common practice to add grain refiners into the alloy melt to promote heterogeneous nucleation and hence achieve effective grain refinement. However, the efficiency of commercial grain refiners is extremely low as less than approximately 1% of the added particles initiate aluminium grains during solidification whil ... More
Presented by Dr. Feng WANG
Computational simulations of solidification microstructures have contributed to understanding of time evolutions of complex morphologies of crystals in a variety of solidification processes. A phase-field method is an effective method in simulating the solidification microstructures such as a dendrite structure, a typical morphology of growing solid in solidification of metals. Importantly, accura ... More
Presented by Ms. Yukimi OKA
The Arvedi ESP process and a variety of produced materials have been continuously developed since the opening of the Arvedi ESP plant in Cremona in 2009 to meet market demands for more sophisticated steel grades. The development of grades for more advanced applications such as advanced high strength steels and multiphase grades is of interest. Dual phase grades such as DP600 are already produced t ... More
Presented by Irene WATZINGER
In Low Pressure casting (LPC), the filling stage is led by gradually increasing the gas pressure above the liquid metal, which is pushed through the pipe and into the mould cavity. In opposite to gravity casting, the LPC filling stage however does not only depend on the filling system and part geometries. By smartly choosing the pressure casting ramp, one could control the filling flow and thus av ... More
Presented by Marie BEDEL
Macrosegregation phenomena in casting processes of metallic alloys generate freckles that limit manufacturing of parts with high mechanical properties. Freckles are particularly detrimental in single crystals (SX) produced for aeronautical applications, such as turbine blades. They generates both structural and composition inhomogeneities. The last generation Ni-based superalloys are more subject ... More
Presented by Mr. Vincent MAGUIN
The industrial sectors of energy and transport require the development of equipment with high levels of safety and performance. These requests compel steelmakers to develop cast products with a high microstructural, chemical and mechanical homogeneity. As part of the SOFT-DEFIS project, collaboration between academic and industrials partners has been developed to optimize steel ingots quality in r ... More
Presented by Mrs. Hanadi ETTROUDI
Due to the excellent performance in oxidation resistance and creep strength of intermetallic compounds (IMCs), the IMCs formation and growth behavior at the liquid Al/solid Ni interface is of great interest in the technological applications of liquid-metal infiltration, hot dipping coating, diffusion brazing, and transient liquid-phase bonding. However, there is no consistent conclusion on format ... More
Presented by Prof. Qiaodan HU
Feathery grains have attracted considerable research interest since they were first observed in semi-continuous casting of industrial aluminum alloys about 70 years ago. Different from the regular columnar or equiaxed morphologies observed in alloy castings, this special crystal structure exhibits the alternant twinned and untwinned lamellae morphology. Previous studies focus on the analysis and c ... More
Presented by Prof. Shuangming LI
The rapid solidification processing is frequently used to fabricate novel microstructures. In this work, the formation of novel microstructures in two Al-Cu alloys, i.e. hypoeutectic Al-26wt%Cu and hypereutectic Al-45wt%Cu alloy, in a steady magnetic field (SMF) was investigated using the conventional quenching technique. It was found that the application of the SMF led to appearance of a bulky θ ... More
Presented by Prof. Chuanjun LI
For directional solidification experiments with low withdrawal rates near and even below the constitutional undercooling limit of the corresponding alloy, a sample is needed which reveals an homogeneous concentration along the sample axis. As stirring in longish samples is diffi-cult, homogenization by rapid solidification is very common. Hereby, the liquid sample is rapidly moved from hot to cold ... More
Presented by Dr. Johann Peter MOGERITSCH
Effective grain refinement strongly depends on the interplay between nucleation potency of nucleant particles (measured by nucleation undercooling), grain initiation behaviour (affected by size, size distribution, spatial distribution and number density of nucleant particles) and solidification conditions (specified by alloy concentrations and cooling rate). Recently, we have made good progress in ... More
Presented by Dr. Feng GAO
Over the past 7 decades, grain refinement of Al-alloys has usually been achieved by enhancing heterogeneous nucleation through the addition of grain refiners (e.g., Al-Ti-B), which contain potent nucleant particles. However, this approach has reached its limit; it is difficult to achieve any further grain refinement. Based on the concept of explosive grain initiation, we have recently developed a ... More
Presented by Dr. Jayesh PATEL
A homogeneous microstructure of as-cast magnesium alloys is desired to improve the formability during their subsequent thermomechanical processing. Owing to its similar crystal structure to Mg, the part of Zr formed by peritectic reaction during solidification was considered to be the most effective nucleants for alpha-Mg. However, regarding the Al-containing magnesium alloys, up to now no suitabl ... More
Presented by Mr. Yuanding HUANG
It has been recently realized that atomic ordering in the liquid adjacent to the substrate (i.e., prenucleation) has a significant implication on the subsequent heterogeneous nucleation process. In this paper, we report an atomistic mechanism of heterogeneous nucleation through structural templating. Using molecular dynamics (MD) simulation, we investigated the process of heterogeneous nucleation ... More
Presented by Dr. Hua MEN
Metal matrix composites (MMCs) can be tailored to produce various combinations of stiffness and strength and have found a wide range of applications where existing materials are not suitable for use in automotive and aerospace industries and many other areas. Stir casting is commonly used for fabricating large quantity of primary MMCs, in comparison to liquid metal infiltration and powder metallur ... More
Presented by Dr. Yan HUANG
With the advent of high-energy X-ray sources, it is now possible to follow solidification processes in three dimensions and as a function of time. The ability to observe and quantify the solidification process in metals on sub-second time scales and micron spatial scales in three dimensions provide fundamentally new insights into this complex phase transformation. Additions of Zn to Al are known ... More
Presented by Peter VOORHEES
When heating steel, its iron content interacts with the ambient oxygen, inevitably forming oxide scales on the steel surface. These scales negatively affect the steel’s surface quality, physical properties, and appearance. In the production of high-quality hot-rolled products, it is imperative to remove these impurities from the metal surface. High-pressure hydraulic nozzles are commonly u ... More
Presented by Mr. Rudolf SCHICK
The mechanical properties of materials are directly related to their solidification structures, so that a precise control of growth process is crucial in engineering. Two types of grain structures are commonly obtained during metal alloy solidification: a columnar grain structure with anisotropic properties, or an equiaxed grain structure with more isotropic properties. A fine and homogeneous grai ... More
Presented by Dr. Guillaume REINHART
Peritectic transitions - characterized by the formation of a secondary phase from decomposition of the primary phase and the melt - are very common in the solidification of metallic alloys. During the peritectic reaction, all three phases are in direct contact, thus forming a trijunction. Already in 1979, Hillert [1] emphasized the important role of the junction force balance in the peritectic rea ... More
Presented by Dr. Janin EIKEN
Laser Additive Manufacturing (LAM) can directly produce near-net-shape metallic components using commercial alloy powders. However, primary solidification during LAM is far from equilibrium due to the ultra-fast laser-powder interaction (<50 ms), mixing of solutes during melting and micro-segregation upon rapid solidification. Our understanding of these phenomena and the resultant microstructural ... More
Presented by Dr. Samuel CLARK
Thermal diffusivity and individual solutal diffusivity of component play a significant role during natural convection dominated solidification of multicomponent alloys. In this study, in situ experimental observations of solidification of a ternary salt solution (water-potassium nitrate-ammonium chloride) are reported. The phase diagram of the ternary salt solution consists of three distinct regim ... More
Presented by Mr. Virkeshwar KUMAR
All growth and casting processes, used for example in the superalloy and photovoltaic industrial sectors, face challenges linked to the grain structure and crystalline defects left during the solidification step when aiming at improving the final desired properties. The post-mortem studies of the solidified ingots provide limited information on the mechanisms occurring during solidification, on th ... More
Presented by Dr. Nathalie MANGELINCK-NOËL
Recent theories suggest the existence of an incubation time, over which a liquid alloy prepares for nucleation by decomposing into compositional fluctuations. In the present work, the incubation time is assumed to be a physical interpretation of Raoult’s Second Law and common depression of the equilibrium freezing temperature by solute addition. The higher the solute content of an alloy, the lon ... More
Presented by Mr. Mohammad POURGHARIBSHAHI
Ming HE 1, 2, Xianliang LI 1, 3, Qingwei WANG1, 2, Qiang WANG 1, * 1 Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China 2 School of Metallurgy, Northeastern University, Shenyang 110819, China 3 School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China * Corresponding author: wan ... More
Presented by Dr. Ming HE
Lamellar eutectic two-phase growth is in principle well understood for alloys in which the solid-liquid and solid-solid interfaces are isotropic. However, there are numerous experimental observations that cannot be explained by theories and numerical models with isotropic interfaces. Examples are the occurrence of lamellar growth directions that markedly differ from the direction of the tempera ... More
Presented by Mr. Mathis PLAPP
The present contribution reviews the recent progress related to the influence of Icosahedral Short-Range Order (ISRO) and icosahedral Quasicrystals (i-QC) formation on the solidification of fcc alloys through minor solute element additions. From intensive crystallographic analysis of multi-twinned region in as-cast Al-based and Au-based fcc alloys, it has been shown recently that a so-called “iQ ... More
Presented by Dr. Julien ZOLLINGER
Secondary metallurgical processes such as Vacuum arc remelting (VAR) are extensively used for production of metal ingots with superior quality. The complex VAR process involves a wide range of physical phenomena including heat transfer with phase change (solidification/melting), Plasma arc, and the interplay between flow and electromagnetic field known as magnetohydrodynamics (MHD). The spatial a ... More
Presented by Dr. Ebrahim KARIMI SIBAKI
During solidification of alloys with a temperature gradient in a stati magnetic field, the thermoelectric magnetic(TEM) force may be induced. The TEM force will produce convection in the molten metal and stress in the solid during the solidification. The convection and stress may play an important role in the formation of the micro-and macro-structures of the alloy. The influence of the thermoelec ... More
Presented by Prof. Zhongming REN
The current study is an effort to develop benchmark experimental and numerical settings for binary alloy solidification, and our initial results are presented in this paper. Controlled solidification experiments in a rectangular side-cooled cavity with analogue transparent aqua ammonia system (H2O+NH4Cl) are performed for different concentration (eutectic, hype eutectic, hyper eutectic solutions) ... More
Presented by Mr. Alok KUMAR
Belt casting as a technology has been suggested as a potential casting method for steels for decades. However it has been hindered by technological capabilities and investment. The potential draw of > 3GJ/tonne reduction in energy this process has on conventional continuous casting has meant that this technology has always shown great potential. With recent improvements and the active mill in Salz ... More
Presented by Dr. Carl SLATER
Supercooled liquids may offer fascinating phenomena as compared with the normal state. In the case of supercooled paramagnetic liquids, completely different phenomena in high magnetic fields have be observed thanks to the high undercooling leading to higher magnetization and very strong magnetic coupling in the liquids. However, due to the restriction of the magnetic field intensity and maximum un ... More
Presented by Prof. JUN WANG
The growth of faceted crystals occurs often in nature and industry, involving always the presence of flow. Insulin, silicon, pyrite, quartz, gallium are only few examples of faceted crystals. The present paper presents a numerical model for the simulation of facetted crystal growth, taken into account the incidence of flow. The growth in facetted crystals is the results of interface kinetics and f ... More
Presented by Mrs. mihaela STEFAN
Chills are used in the production of steel castings as a thermal aid to promote directional solidification in casted sections. This study will review microstructure and thermal circumstances of the internal chill interface where the chill is intended to be incorporated into the structure of the cast section. The conditions for interface coherency of cast steel sections from 25 to 50mm will be show ... More
Presented by Dr. Charles MONROE
In Fe-C alloys (<0.5mass%C), it has been considered that the solidification of δ phase (BCC) was followed by the peritectic reaction (L+δ -> γ). Radiography proved that delta phase transformed to gamma phase in the solid state (massive-like transformation). Recently, time-resolved tomography (4D-CT) has been developed by different groups. This technique allows us to perform 3D observation of so ... More
Presented by Prof. Hideyuki YASUDA
Unidirectional solidification experiments were performed according to the vertical, upward Bridgman method by using Al-4 wt.% Cu alloy. The diameter of the cylindrical samples was 8 mm and their length was 120 mm. Three different constant sample-movement velocities were used during the experiments. The temperature of samples was measured by 13 pieces of NiCr-Ni thermocouples located at different p ... More
Presented by Mr. Jenő KOVÁCS
The microstructural pattern evolving during directional solidification is of high interest as it directly influences the material properties. During the ternary eutectic directional solidification of Al-Ag-Cu, besides the evolution of different patterns the solubility of silver in the $\alpha$-aluminum phase changes by $50\,\%$ directly below the eutectic point. This leads to a change of the ph ... More
Presented by Dr. Johannes HÖTZER
Band segregation has been found in the H13 die steel produced by the electroslag remelting (ESR) technology. Chemical and metallographic studies have been carried out on a one ton ESR ingot of H13 die steel, so as to understand the formation mechanism of the band segregation. The results indicate that the oxygen and nitrogen contents in the ingot increase by 47.2% and 15.7%, while the sulfur conte ... More
Presented by Dr. Qiang WANG
Recent advancements in the phase field theory predict slow and fast regimes of crystal growth from melts and solutions [1]. We analyze kinetics of crystal interfaces invading undercooled melts using traveling wave solutions derived from phase field theory of fast phase transformations. These solutions are compared with data kinetics of molecular dynamics simulations [2-4] obtained for slow and rap ... More
Presented by Peter GALENKO
Grain growth, a competitive growth of crystal grains that occurs after or simultaneously with solidification, is one of the most important phenomena in controlling the microstructure of polycrystalline materials. The fundamental process underlying grain growth is the migration of grain boundaries; thus, the growth behavior is largely dominated by the properties (energy and mobility) of grain bound ... More
Presented by Mr. Eisuke MIYOSHI
In recent years, significant progress has been achieved in additive manufacturing processes. Among these technologies, large attention has been generated for Laser Beam Melting (LBM). This process provides the possibility to develop parts of complex geometries with well-suited mechanical strengths. It is also able to develop pieces on a wide range of metallic and non-metallic materials and meets t ... More
Presented by Dr. Gildas GUILLEMOT
Laser metal deposition is an additive manufacturing technique for fabricating complex metal components layer by layer. The complex thermal behavior during this process results in the complex microstructure evolution, which directly affects the final mechanical properties of the products. Numerical modeling offers a cost efficient way to better understand the related complex physics in laser metal ... More
Presented by Dr. Junjie LI
Chemical inhomogeneity and inclusions are the most severe defect types in bearing steel which have great influences on the ingot quality and final product properties. Based on a series of full-dissections of steel ingots varying with composition and weight, numerous experimental characterizations by SEM, EPMA, TEM, ASPEX and 3D Micro-CT techniques and multi-scale simulations, a new driving force, ... More
Presented by Prof. Dianzhong LI
A 3D model of equiaxed solidification is applied to horizontal direct chill casting (HDC) of Al-4.5 wt% Cu slabs. Unlike vertical direct chill casting, HDC can operate as a continuous process, allowing for increased productivity. The flow field and macrosegregation in HDC are asymmetric along the slab thickness due to the asymmetry in heat extraction and casting perpendicular to gravity. Previous ... More
Presented by Prof. IGOR VUSANOVIC
Isomorphic inoculation has recently been introduced by the authors as a successful method to grain refine cast titanium aluminides [1]. Analyses of the cast grain size together with introduced particles size distributions revealed anomalously high grain refinement efficiency which was attributed to the particles breaking up during the holding stage prior to solidification [2]. In the present work, ... More
Presented by Dr. Julien ZOLLINGER, Dr. Jacob KENNEDY
A two dimensional model for the simulation of dendritic growth in binary alloys is developed. Phase field model is used to derive the system of partial differential equations describing the temporal evolution of the solid-liquid interface and concentration field. Quantitative modeling is assured by the use of thin interface limit of the isothermal phase field model. Meshless local radial basis fun ... More
Presented by Mr. Tadej DOBRAVEC
Mesoscopic envelope models rely on the description of the complex morphology of a dendritic grain by an envelope, which is a smooth surface connecting all of the dendrite tips. This simplification in the description of the grain shape enables to reduce requirements on spatial resolution and allows for modelling of larger number of grains or domains, when compared to more detailed microscopic appro ... More
Presented by Dr. Alexandre VIARDIN
Additive manufacturing (AM) is inducing some kind of next industrial revolution. Components develop layer by layer in a powder bed by selective beam melting according to 3D model data. This technique allows manufacturing of highly complex components and is especially interesting for high performance materials that are difficult to process in conventional technologies. Nevertheless, AM is challenge ... More
Presented by Prof. Carolin KÖRNER
Microsegregation has a great influence on properties of materials such as mechanical and corrosive properties and it entirely depends on size and morphology of solidification microstructure. Although a number of efforts have been devoted to understanding and controlling of microsegregation in alloy systems, little has been clarified about microsegregation behavior at grain boundaries formed by gro ... More
Presented by Mr. Jaehoon LEE
Type: Poster
It is essential to predict the microstructure of the casting materials since it does not only influence on the mechanical properties, but also determine the process parameters during the casting process. The cellular automata (CA) is the one of the best efficient methods to analyse the microstructures by demonstrating the nucleation and grain growth during the solidification of materials. In this ... More
Presented by Prof. Jonghun YOON
Our comprehensive understanding of binary eutectic solidification is largely due to years of extensive studies of many metallic and non-metallic systems. Recently, there has been increasing effort to understand ternary eutectic solidification due to the potential for refinement of microstructure resulting from increased number of co-existing crystalline phases during the solidification of multicom ... More
Presented by Prof. Isaac CHANG
Piston Al-Si eutectic alloys are used to produce direct-chill cast billets for subsequent forging. Because of a very complex composition and multi-phase heterogeneous structure, it is necessary to control the formation of primary and eutectic compounds either through alloying or casting conditions (or both). In this study we used ultrasonic melt processing above of across the liquidus line to affe ... More
Presented by Ms. Suwaree CHANKITMUNKONG
The growth dynamics of multiple equiaxed dendrites in a thin metallic sample is studied using *in situ* synchrotron X-ray imaging of Al-4 wt.%Cu alloy solidification experiments and corresponding full-scale three-dimensional (3-D) phase-field (PF) simulations. The tip growth velocity *V*, tip radius *ρ*, the secondary dendritic arm spacing (SDAS) *λ*$_2$ and the total solid fraction *f*$_s$, are ... More
Presented by Mr. Tong Zhao GONG
Great efforts have been paid by the automotive industry towards producing lightweight vehicles. Aluminum alloys, with high strength-to-weight ratio, has been one of the main materials in achieving these weight demands. This work focuses on compound casting between A356 alloy melt and profiles of AA6xxx wrought aluminum alloys through a gravity casting process. With the incorporation of a wrought a ... More
Presented by Ms. Aina Opsal BAKKE
The formation of eutectic microstructures, composed of two phases or more, is often encountered during the solidification of industrial alloys. Fraction and characteristics of this structure have consequences on the subsequent phase transformations, mechanical strength and final end-use properties of metallic pieces. Consequently, estimation of eutectic growth kinetics is required in order to pred ... More
Presented by Dr. oriane SENNINGER
Powder bed fusion processes in additive manufacture (AM) of metals typically involve solidification in high thermal gradients, leading to unwanted anisotropic columnar growth and high residual stress in as-printed components. Equiaxed solidification can alleviate such problems but is difficult to achieve due to the thermal fields naturally evolving in typical AM processes. Pre-heating of the powde ... More
Presented by Prof. David BROWNE
Applying magnetic field during solidification of metallic alloys process under high thermal gradient may influence drastically microstructures of solidified metal. In fact, Magnetic Lorentz forces due to the coupling of electromagnetic field with thermo-electric currents are acting on the movement of solid grains and on the movements of fluid around grains, which finally produce re-organized and m ... More
Presented by Dr. YVES DU TERRAIL COUVAT
We have performed the large-scale molecular dynamics simulations for nucleation, solidification and microstructure formation [1] and found various new insights such as the heterogeneity in homogeneous nucleation [2] and decrease of the averaged grain boundary mobility during the grain growth [3]. Although these studies were performed using pure metallic system for simplicity, the most of practical ... More
Presented by Prof. Yasushi SHIBUTA
Since many of metallic materials are formed through solidification from the undercooled melt, it is indispensable to control the nucleation at the initial stage of solidification. In actual material production processes, heterogeneous nucleation is often promoted by inoculating grain-refiners in the melt. In this study, the effect of grain-refiners of Ti and Ti3Al solid particles on the heterogene ... More
Presented by Mr. Takuya FUJINAGA
Thermal-solutal convection necessary occurs during the terrestrial solidification of alloys. Thanks to the recent progress in the in-situ observation technique using X-ray radiography, the direct observation of dendrite growth under high temperature has been made possible. In the in-situ observation, however, it is difficult to see the liquid flow during the dendrite solidification. In order to cl ... More
Presented by Mr. Shinji SAKANE
Formation process of equiaxed structure is quite complicated phenomenon. The most difficult point in the modeling of the equiaxed structure formation process would be a motion of dendrites. In our previous study, we succeeded in expressing the growth of a single dendrite accompanying the motion by coupling phase-field method, lattice Boltzmann method, and equations of motion [R. Rojas, T. Takaki, ... More
Presented by Prof. Tomohiro TAKAKI
The 3-D morphology, orientation selection and behind mechanism of magnesium alloy dendrite were investigated by performing multiscale mathematical simulations. The results showed that the α-Mg dendrite prefers to grow along <11-20> basal direction and <11-23> nonbasal direction, and the resultant 3-D dendritic morphology exhibits a typical 18-primary branch pattern. Such dendritic microstructu ... More
Presented by Dr. Jinglian DU
This talk will review recent progress to bridge the gap between phase-field modeling on the microstructure scale and grain structure modeling. While phase-field modeling has been used successfully to model quantitatively dendritic alloy microstructures, only volumes up to about a millimeter cube (or even smaller for concentrated alloys) can be simulated even on today’s massively parallel compute ... More
Presented by Prof. Alain KARMA
In this talk, we will review recent developments using the multiscale Dendritic Needle Network (DNN) approach for dendritic growth, with a particular emphasis on its application to convective transport in the liquid phase. The DNN method was developed for the modeling of dendritic growth of hierarchical needle-like dendritic crystals, which typically form at low solute supersaturation or undercool ... More
Presented by Dr. Damien TOURRET
Twin roll casting (TRC) is an energy efficient way of producing Mg alloy sheet for lightweight applications. However, unfavourable microstructural features, such as columnar grains and centreline segregation, are present in the as-cast alloy sheet. By modelling the effects of casting parameters, melt conditioning and material parameters on microstructure development, feedback can be provided to op ... More
Presented by Ms. Yi QIU
Al-Mn-Fe intermetallics are important for the corrosion resistance of cast Mg alloys but there have been few studies on their solidification mechanisms or microstructure development. Here EBSD, deep etching and FIB-tomography are combined to study the nucleation and equaixed growth crystallography of B2-Al(Mn,Fe), Al8Mn5, and Al11Mn4 in Mg-Al-Mn-based alloys. It is shown that twinning readily occu ... More
Presented by Dr. Chris GOURLAY
The current work, describes a numerical methodology to obtain deeper understanding of the kinetics of solidification, the formation of intermetallic phases and the dynamics of Al melt infiltration into porous iron preforms. The model was calibrated against test cases from infiltration experiments performed using the centrifugal casting process with liquid Al on additively manufactured SLM Fe-prefo ... More
Presented by Dr. Ralf BERGER
Melt conditioning, i.e. shearing of liquid metal using a rotor-stator device, refines the grain structure without the need for grain refiners. Melt conditioning as applied to direct-chill (DC) casting, forming the MC-DC process, has recently been demonstrated to be an effective method of producing high quality light alloy billets. The optimisation of melt conditioning parameters through experimen ... More
Presented by Dr. Bruno LEBON
Complex part geometries and the high injection speed during the high pressure die casting (HPDC) process cause non-equilibrium solidification and vigorous fluid flow with free surface fragmentation and splashing. This results in a high probability of forming defects, in particular porosity. Defects tend to distribute very randomly and irregularly, which leads to a substantial variability in the me ... More
Presented by Dr. Kun DOU
The presence of small amount of the Fe in the Al-Si alloy causes the formation of the platelet-shaped Al5FeSi intermetallic phase, which is detrimental to the alloy mechanical properties. A series of directional solidification experiments on Al-Si-M alloy were performed under diffusion or controlled convection to study the interaction of fluid flow and the formation of the intermetallic phase and ... More
Presented by Mr. Haijie ZHANG
The Interdependence model [1] predicted that nucleation would occur in waves of events with regions of no nucleation in between each wave. The waves continue to form until nucleation covers the sample. The cause of this phenomenon was attributed to the formation of a nucleation-free zone which incorporates solute suppressed nucleation and inhibited nucleation zones. Recent real-time synchrotron x- ... More
Presented by Prof. David STJOHN
Process stability during continuous casting is crucial in order to obtain homogeneous and constant conditions for the fluid steel to solidify evenly in the mold. In highly productive slab casters, the utilization of the submerged entry nozzle (SEN) feeding the molten steel into the casting mold is often maximized. Before the SEN is taken out of operation, it undergoes wear and erosion. Particula ... More
Presented by Mr. Martin SEDÉN
The scientific aim of the present work is to obtain fundamental information on chemical homogenisation process of liquid steel with alloy additions in the tundish. For alloy feeding to liquid steel pulse step alloying method was applied. Author checked the effect of hydrodynamic conditions occurs in the internal working space of tundish on the process of alloy mixing with liquid steel. Within the ... More
Presented by Prof. Adam CWUDZINSKI
A numerical model was developed to predict solidification grain structures and macrosegregation based on a three-dimensional cellular automaton finite different method coupled with flow calculation of natural convection and shrinkage flow. Direct simulations of grain growth and macrosegregation were performed using the numerical model. First, in order to confirm the effect of natural convection, s ... More
Presented by Prof. Yukinobu NATSUME
The ice-templating of porous materials has received a great deal of attention during the past few years. This simple process, where a material suspension is simply frozen and then sublimated, provides materials with unique porous architectures, where the porosity is almost a direct replica of the frozen solvent crystals. The basic principle of ice-templating is the assembly of a second phase, usua ... More
Presented by Dr. Sylvain DEVILLE
We provide direct visualization of the microstructural evolution during heating Al-Mn alloy by synchrotron radiography. The bubbles vary gradually from irregular to subglobose and finally deform into spherical shape with increasing temperature. And some bubbles grow, while some others gradually became small or even all of them disappear during heating. There are two different reasons for bubble gr ... More
Presented by Dr. Wenquan LU
One of the crucial ingredients of today’s numerical simulation technologies is their cross-scale and cross-platform capabilities for material processes applications. Handling of simultaneous evolution paths at various scales\times (i.e., multi-scaling) during complex material processes where materials microstructure & microchemistry interacts with meso and macro events, is one of awkward challen ... More
Presented by Prof. Amir HORR
As it was previously reported, a numerical model was applied to simulate the behaviour of the packed bed of equiaxed crystals [1]. At the high temperatures metals tend to follow a viscoplastic law according to Bellet et. al [2]. Thereby based on the authors developments a viscoplastic stress model was applied to the thin slab casting process. In this idea the solidifying shell represents a ‘cree ... More
Presented by Dr. Alexander VAKHRUSHEV
The endogenous inclusion during solidification may generate from the combination of solute and non-metallic element, i.e, O, S, therefore the formation of such inclusion would take effect to global macrosegregation. To legitimately examine the interaction between endogenous inclusion and macrosgregation, an inclusion-combined macrosegregation model, which coupling the inclusion growth theory with ... More
Presented by Ms. Duanxing CAI
The inhomogeneity in large ingots not only decides the final properties of the product, but also restricts downstream hot working processing severely. It is very important to improve the homogeneity of ingots for saving energy, improving material utilization ratio, increasing performance of component, and the construction of key equipment. In this research, the evolutions of general inhomogene ... More
Presented by Prof. Jianguo LI
Solidification during twin-roll casting happens by cooling of the melt between two counter-rotating rolls, where the molten alloy is constantly fed in. For an inoculated Al-melt, nucleation and growth of grains lead to a gradual increase of solid fraction, so that a coherent solid network forms. Depending on the process condition this solid network might then be subjected to compression within the ... More
Presented by Prof. Andreas LUDWIG
Cast components generally show a heterogeneous distribution of material properties, caused by variations in the microstructure that forms during solidification. Variations caused by the casting process are not commonly considered in structural analyses, which might result in manufacturing of sub-optimised components with unexpected in-use behaviour. In this paper, we present a methodology which ca ... More
Presented by Mr. Johan JANSSON
The comparison between the volume changing during the solidification of lamellar graphite (LG) cast iron, and spheroidal graphite (SG) cast iron shows large differences. Linear Variable Differential Transducer (LVDT) was used in the sand mould casting to measure the differences in the volume changing. The experimental results will be presented and analysed. A careful microstructural analysis show ... More
Presented by Dr. Abel TADESSE
Computational simulation and modelling of different phenomena in casting has greatly helped to solve practical problems in industrial casters and to improve process practices and control. Altogether, we still need deeper understanding of the complex solidification phenomena and transformations of microstructure to respond to the increasing requirements. For this purpose, advanced numerical simulat ... More
Presented by Dr. Ville-Valtteri VISURI
Ultrasonic processing (USP) during direct-chill casting of light alloys is typically applied in the sump of a billet. This approach, though successful for structure refinement and modification, has two main drawbacks: (a) mixture of mechanisms that rely heavily on dendrite fragmentation and (b) limited volume that can be processed by a single ultrasonic source. We suggest moving the location of US ... More
Presented by Prof. Dmitry ESKIN
Ternary Fe-Cr-Ni steel alloys often exhibit a multi-step transformation known as double recalescence where primary ferrite converts to austenite during rapid solidification processes such as casting and welding. In addition to the volume free energy associated with undercooling between the phases, the free energy driving the transformation comes from two additional sources that are retained withi ... More
Presented by Prof. Douglas M. MATSON
TESA, Thermoelectric Solidification Algorithm, is a bespoke numerical code originally designed to capture the effect of Thermoelectric Magnetohydrodynamics in high undercooled growth. The code is actively being developed with parallelisation, a cellular automata method to capture micro-macroscale solidification and the Lattice Boltzmann method to resolve the hydrodynamics. This paper describes the ... More
Presented by Prof. Koulis PERICLEOUS
Selective Laser Melting (SLM), the most advanced metal additive manufacturing (AM) process, produces metal parts directly from a CAD file. Currently, the main bottlenecks preventing the SLM parts from competing with traditionally manufactured metal parts include the defects, such as porosity, low surface finish quality, high residual stresses and anisotropy. Though post-build microstructural a ... More
Presented by Dr. Arvind KUMAR
Abstract PERED® Direct Reduction technology is the new technology in the world. Iran country developed direct reduction PERED® technology for decreasing capital cost and energy saving. Iron oxide pellets reduced in the shaft furnace. Top gas return from furnace after cleaning in scrubber is divided to fuel and process gas. Process and natural gas mixed together (feed gas) after preheat in hea ... More
Presented by Mrs. Fatemahmahnaz MOHSENZADEH
Permeability for flow of interdendritic liquid is a very important parameter in a macrosegregation prediction during alloy solidification. For systematical permeability prediction in various solidification conditions, a numerical simulation coupling a phase-field method and computational fluid dynamics would be the most promising approach. In our previous study, we have developed a permeability pr ... More
Presented by Mr. Yasumasa MITSUYAMA
Directional solidification experiments were recently performed on-board the International Space Station ISS on samples from the ternary alloy Al-18at%Cu-1at.% Ag. The experiments were designed to produce extended eutectic grains right from the onset of growth, using appropriate seed material and further included a transition from planar to cellular eutectic growth. The presentation will focus on t ... More
Presented by Dr. Ulrike HECHT
Nucleation of crystalline materials, the starting point for crystal formation from melts, has long been an important issue in condensed matter physics and materials science. Nucleation plays a key role in determining the microstructures and mechanical properties of crystalline materials; therefore, controlling nucleation is a very effective way for regulating the macrostructures of materials for s ... More
Presented by Prof. Jincheng WANG
Wire and laser additive manufacturing (WLAM) is a potentially disruptive manufacturing technique in which large metallic materials can be fabricated layer by layer. Understanding the dynamic evolution of primary cellular/dendritic spacing in the laser melt pool is significant from a technological viewpoint because primary spacing is one of the foremost parameters that control the final mechanical ... More
Presented by Mr. Wang ZHENG
Modelling of non-equilibrium solidification is of singular importance in microstructure control, which however owing to the complex systems with complex additional constraints is still an open problem. In this work, the thermodynamic extremal principle was applied to solve the complex additional constraints self-consistently in thermodynamics for both binary and multi-component alloys. Consequentl ... More
Presented by Prof. Haifeng WANG
After solidification, grain growth occurs in the metallic materials, in general. It is very important to understand grain growth as well as solidification in order to control the mechanical properties of metallic materials. Abnormal grain growth(AGG), in which some grains preferentially grow to be extremely large, often occurs during cooling and isothermal holding at high temperatures after the so ... More
Presented by Mr. Takahisa KINOSHITA
Due to the significant effects of the underlying microstructure on the material properties, accurate understanding of microstructure evolution in solidification processes has attracted lots of attentions in recent years. The low melting point of the ternary eutectic Bi-In-Sn alloy has lead to accurate in situ observations of its solidification process in experimental studies. Although these observ ... More
Presented by Mr. Kaveh DARGAHI NOUBARY
The solidification of alloys shows a large variety of different microstructures depending on the material system and processing conditions. Since materials properties such as tensile strength are dependent on the microstructure, its prediction is a topic of high interest in order to produce materials with tailored properties. Whereas theory is capable of investigating simple geometries, simulati ... More
Presented by Mr. Marco SEIZ
We have used high temperature laser-scanning confocal microscopy by utilizing a concentric solidification technique to observe in-situ and in real time solidification events and high-temperature microstructural development, with a special emphasis on high temperature phase transformations. However, the solidification and subsequent solid-state transformation kinetics, on both heating and cooling, ... More
Presented by Mr. Dasith Deshan LIYANAGE
The preferred growth direction of crystal in solidification of metallic materials is mainly determined by anisotropy of solid-liquid interface energy, g(n), where n represent the crystallographic orientation normal to the solid-liquid interface. The anisotropy of g(n) is described by anisotropy parameters e1 and e2 that characterize <100> and <110> growth, respectively. Effect of e1 has been consi ... More
Presented by Mr. Geunwoo KIM
The properties of a material are mainly defined by their chemical composition and by the underlying microstructure. Depending on the process conditions during the directional solidification and the applied material system different microstructures evolve, which are suitable for the demands of specific applications. Instable growth conditions during the directional solidification can lead to an inc ... More
Presented by Mr. Michael KELLNER
The phase-field approach can be used to model the motion of interphase boundaries, even where there is deviation from equilibrium. The evolution of grain structure in polycrystalline materials, on the other hand, can be best described through probabilistic approaches such as the Monte-Carlo Potts model. The present contribution reports on a model of microstructure evolution where these approaches ... More
Presented by Prof. Hamid ASSADI
During the solidification of ternary eutectics, three solid phases form simultaneously from the melt. One system often employed to study this complex multi-phase solidification behavior is ternary eutectic $Al$-$Al_2Cu$-$Ag_2Al$. In this system the solubility of silver in the α-Al phase decreases by approximately 50% in a range of less than 20 K below the ternary eutectic temperature. This di ... More
Presented by Prof. Amber GENAU
In gear material in automobiles, both the wear-resistance around surface and the toughness in central part are required. By using gas carburization technique [1], it is possible to obtain a high carbon content that causes carbide precipitation at surface, while maintaining the original carbon content at base part. That is, the dual industrial demand is satisfied. In recent years, the requirem ... More
Presented by Prof. Hongwei ZHANG
The control of the carbon macrosegregation level in steel ingots is important for the structural integrity of the final component. Previous studies using the SOLID® multiscale modelling software [1] have shown that in order to obtain predictive results for the macrosegregation and the grain structure (CET, grain morphology) in steel ingots, a model needs to account for fragmentation of columnar d ... More
Presented by Dr. Benjamin GERIN
Solidification microstructure of metal castings determines their as-cast mechanical properties. Accurate prediction of as-cast grain structure and key defects (such as porosity) is critical in the design and manufacturing of metal castings using an integrated computational materials engineering (ICME) approach. In this talk, a three-dimensional (3-D) model based on cellular automaton (CA) and proc ... More
Presented by Prof. Alan A. LUO
Prenucleation refers to the phenomenon of atomic ordering in the liquid adjacent to the liquid/substrate interface at temperatures above the nucleation temperature, which becomes the precursor for the subsequent heterogeneous nucleation process through structural templating. Understanding of prenucleation is therefore of both scientific and technological importance. Based on recent investigations ... More
Presented by Dr. Changming FANG
Under a NASA-ESA (European Space Agency) collaborative research project, MICAST (Microstructure formation in casting of technical alloys under a diffusive and magnetically controlled convection conditions), three Al-7wt% Si samples (MICAST-6, MICAST-7 and MICAST 2-12) were directionally solidified aboard the International Space Station to determine the effect of mitigating convection on the primar ... More
Presented by Prof. Surendra TEWARI
This paper reports on the development of Solidification Continuous Cooling Transformation (SCCT) diagrams relating the solidification paths to the inherent microstructures of binary and ternary alloys. The methodology is based on the quantification of a solidified microstructure for its various phase fractions. This measured data is combined with well-established solidification models to yield u ... More
Presented by Prof. Hani HENEIN
To unearth the fundamentals in solidification requires the use of advanced experimental methodologies and computational modelling. On the experimental side, synchrotron based high speed X-ray tomography, which can capture a tomogram (3D volume) in seconds, is a powerful tool to study solidification in real-time, allowing the visualization of solidifying alloys as 3D movies or 4D (3D plus time) ima ... More
Presented by Dr. Biao CAI
Type: Poster
Spherical pre-alloyed Nb-20Si-24Ti-2Cr-2Al (at.%) powders were prepared by plasma rotating electrode processing (PREP). The diameters of the pre-alloyed powders ranged from 45 μm to 380 μm. The microstructure and surface oxides of Nb-Si based alloy powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and Auger electron spectr ... More
Presented by Mr. Lina JIA
Al-Cu droplets of eutectic composition with different purity levels, were rapidly solidified by Impulse Atomization. A wide range of microstructural scales was obtained at different cooling rates and undercoolings. The micrographs of the investigated microstructures revealed two distinct zones of different structural morphologies: An irregular eutectic morphology developed during recalescence foll ... More
Presented by Prof. Hani HENEIN
This study aimed in combining the material properties and numerical modelling techniques through practical application to provide understanding of surface edge cracking caused by V(CN) precipitation to optimize and enhance the yield of the continuous bloom caster at ArcelorMittal Ruhrort. The investigation for this work is carried out on three different micro-alloyed steel grades; one of them bein ... More
Presented by Dr. Esra ERDEM HORNAUER
Recent Advances in Understanding the Early Stages of Solidification Z Fan BCAST, Brunel University London, Uxbridge, Middlesex, UB8 3PH, UK (zhongyun.fan@brunel.ac.uk) Solidification of single phase alloys occurs in a number of distinctive stages during the cooling process. For isothermal solidification these may include prenucleation (atomic ordering in the liquid adjacent to the liquid/s ... More
Presented by Prof. Zhongyun FAN
The nucleation and Growth behaviors of primary Si particles in hypereutectic Al-Si-Cu alloys solidified under near-isothermal melt and constant cooling rate condition, have been studied by in-situ X-radiography. The influences of cooling rate and addition level of P on the nucleation temperature, maximum nucleation undercooling, nucleation rate, growth velocity and morphology development of prima ... More
Presented by Dr. Yijiang XU
An in-situ study on the directional solidification of an inoculated Al-20 wt%Cu alloy under well controlled constant cooling rates and temperature gradients has been carried out using a microfocus X-radiography set-up. The influences of temperature gradient and cooling rate on the heterogeneous nucleation rate and growth kinetics of equiaxed grains have been studied quantitatively. It is shown tha ... More
Presented by Prof. Yanjun LI
Directionally solidified binary eutectics are of great practical interest as self-organized composite materials with tunable microstructural features. In a first approach, eutectic microstructures can be classified into rod-like and lamellar ones. Their formation dynamics, which results from a complex diffusion controlled dynamics of coupled-growth front patterns, has been extensively studied by i ... More
Presented by Mrs. Silvere AKAMATSU
Grain refinement of Mg alloys is usually achieved through enhanced heterogeneous nucleation by chemical inoculation. Albeit the most commonly used grain refiner for Mg alloys, Mg-Zr master alloy works only for Al-free Mg alloys and suffers from high material cost and low alloying efficiency. Recently, our research demonstrates that the native oxide particles in Mg-alloy melts can be harnessed for ... More
Presented by Mr. Shihao WANG
Solid-liquid interfacial properties of Fe-Cr alloy are investigated by molecular dynamics simulation using an EAM potential. First, solidus and liquidus compositions with respect to temperature were estimated as follows. The solid-liquid coexisting system with the same concentration as the initial state was relaxed under the constant pressure and temperature (NPT) condition. Calculations were carr ... More
Presented by Mr. Ueno KENSHO
Experiments performed in the International Space Station have evidenced oscillatory modes for the solidification of a succinonitrile-based transparent alloy. These oscillations have been studied by phase-field numerical simulations that allowed a better understanding of their origin [1-2]. A recent re-examination of the experimental data showed that, depending on the misorientation of the cryst ... More
Presented by Mr. Jean-Marc DEBIERRE
The foundry engineering still needs new cast materials of improved properties. These can be achieved by elaborating completely new alloys and metal matrix composites or by elaborating the alloys/composites basing on the already very well-known matrixes. The good example of the latter solution are high-aluminium zinc (H-Al Zn) and high-zinc aluminium cast alloys (H-Al Zn). Both of these groups show ... More
Presented by Prof. Witold K. KRAJEWSKI
Numerical simulation of casting filling process with complex shape is time-consuming. Compared with the traditional SOLA method, the lattice Boltzmann method (LBM) calculates the pressure field by the particle distribution functions instead of the correction of velocity and pressure field, which greatly simplifies the calculation process. In addition, the LBM provides a flexiable approach which ca ... More
Presented by Mr. Yongjia ZHANG
The simultaneous prediction of macrosegregation and columnar to equiaxed transition (CET) in metal casting is still an important challenge. One of the open questions is the role of melt convection on the CET and the effect of the CET on macrosegregation. A three-phase Eulerian volume-averaged model for macrosegregation and CET is developed. The model uses our recently-developed accurate constituti ... More
Presented by Prof. Christoph BECKERMANN
**Abstract:** A virtual submesh cellular automata method is established to reduce the computational mesh induced artificial anisotropy with high efficiency and the method is applied to simulate the microstructure evolution during laser melting additive manufacturing. The additive manufacturing process is divided into three parts during simulation: random powder deposition, laser melting and rapid ... More
Presented by Mr. Ling SHI
Numerical simulation technology has been widely used in the field of casting because of its visibility and forward-looking. However, for numerical simulation prediction of complex shape castings, the designer usually considers pouring under ideal conditions. The thermal property parameters used are uniform standardized parameters, and less consideration is given to the physical property parameters ... More
Presented by Mr. Jianxin ZHOU
The grain boundary groove method has been successfully used to measure solid-liquid interfacial energies, σsl, experimentally for binary eutectic, peritectic systems, multi-component systems as well as pure materials, for opaquate materials as well as transparent materials. It was shown that the grain boundary groove method can be use to obtain, σsl, for any alloy system provided that the prepar ... More
Presented by Dr. Elif YILMAZ
One of the most powerful tools for studying the development of microstructures is the CALPHAD (Calculated PHAse Diagrams) method because it comprises information derived from thermodynamic principles, presented in a form that makes the data readily accessible. It is much easier and less time consuming to perform these thermodynamic calculations with any of the available software rather than trying ... More
Presented by Dr. Begoña SANTILLANA
γ-TiAl alloys are regarded as promising candidates in aero and automobile industry due to their superior properties including low density, high specific strength, excellent oxidation resistance and creep strength. However, the application of these alloys is limited by the problems such as micro-segregations, inhomogeneous microstructure, texture and severe cracking tendency. In the article, the e ... More
Presented by Prof. Kou HONGCHAO
Free machining alloys containing soft immiscible phases, like lead (Pb) and bismuth (Bi), in the aluminium matrix are of great industrial interest. It is crucial to develop a method to tailor the distribution of the immiscible phase particles in the final solidified structure in order to provide enhanced machinability while keeping levels of Pb and/or Bi additions low. The size and homogeneity of ... More
Presented by Dr. Nilam BAREKAR
Traditional aluminium casting alloys are based on binary eutectic systems with additions of minor alloying elements for improved castability and mechanical properties. The increasing demand for high strength aluminium casting alloys has led to several studies of ternary eutectic aluminium alloy systems, such as Al-Si-X (X = Sn, Ge, Cu) for the formation of bulk nano/ultrafine composite microstruct ... More
Presented by Mr. Qing CAI
Solidification cracking is a key phenomenon associated with defect formation during welding, casting and some of the additive manufacturing process. To elucidate the failure mechanisms, solidification cracking during arc welding of steel are investigated in situ with high-speed, high energy, synchrotron X-ray radiography approach. Ex situ tomography is then implemented to rebuild and analyse the 3 ... More
Presented by Mr. Jun LI
Twin roll casting (TRC) of Mg alloys has been investigated during last decade as viable processing route to producing Mg sheet for applications where light weighting is of importance. The solidification controlled, melt conditioned low force twin roll casting (MC-TRC) processes developed within BCAST provides a different approach to twin roll casting compared with that of the conventional TRC proc ... More
Presented by Dr. Chamini MENDIS
Direct chill (DC) casting of engineering alloys usually requires the deliberate addition of grain refiners to produce a fine and uniform as-cast microstructure. However, it has been demonstrated that such grain refiners have very low efficiency, for instance, typically less than 1 pct of the added TiB2 particles are active for nucleation of the alpha-Al phase during solidification. In addition, ... More
Presented by Dr. Hu-Tian LI
Selective laser melting (SLM) is a commonly-used additive manufacturing technique, which generally consists of the melting of the powder and of the solidification of the molten pool. The SLM process is being widely investigated using both experimental and modeling methods. Until now, the focus has been on the heat transfer and liquid flow in the molten pool, on defects and on the properties of the ... More
Presented by Dr. Yuze LI
Additive manufacturing by Laser Powder-Bed Fusion (LPBF) is accompanied by solidification under large thermal gradients and cooling rates. As a consequence, solidification morphologies between dendritic with only limited sidebranches or rather cellular pattern are commonly observed. The growth regime is characterized by Péclet numbers of order or larger than 1 (with cell tip radii of order or lar ... More
Presented by Guillaume BOUSSINOT
The modelling of solidification processes in combination with fluid flow is one application of ANSYS Fluent. The solidification is modelled with the enthalpy porosity technique. Therefore, the fluid flow is damped similar to a flow through a porous media of dendrites. For the numerical simulation of remelting processes like electro slag remelting or vacuum arc remelting ANSYS Fluent is used due t ... More
Presented by Mr. Moritz EICKHOFF
DISTEMP solidification numerical model of the continuous casting steel has been a useful tool to explain billet surface and internal quality at Sidenor steel company. Work has been carried out along the years to adjust the appropriate heat transfer coefficients in the mould and secondary cooling to get a reliable description of the CC billet solidification. The numerical model has assisted to exp ... More
Presented by Dr. Gonzalo ALVAREZ DE TOLEDO
Niobium silicide-based composites, in the application of gas turbine blades, promise significant efficiency improvements compared to current Ni-based alloys. The higher temperature capability would allow the engine to run at a higher temperature than that of current alloys, increasing engine efficiency. Nb-Si based composites possess a lower density, due to the presence of ceramic phases such as N ... More
Presented by Mr. Adam ALLEN
Low pressure turbine blades (LPT) made by centrifugal casting from titanium aluminides require demanding process control, as to achieve desired solidification microstructures. The columnar-to-equiaxed transition (CET) and the related texture are of special interest. In the joint European Project “GRADECET” they were investigated in μg, 1g and hyper-g conditions. Solidification experiments of ... More
Presented by Mr. Can HUANG
Super austenitic stainless steels are widely used in hostile environments, as in seawater desalination and paper manufacturing plants, in which an excellent corrosion resistance is required. These steels require a fully austenitic microstructure at room temperature. During processing it may be possible to form Cr- and Mo-rich intermetallic undesirable precipitates that lower both mechanical proper ... More
Presented by Mr. Raphaël MARIN
The oxidation properties of cast iron were reported to sharply increase if the aluminum content exceeds 6–8%, but the applications of such alloys are still limited due to the formation of free complex carbides of iron and aluminum which renders the alloy very brittle and unmachinable. However, the factors affecting the structure of such alloys are still far from being well studied. This paper ... More
Presented by Prof. Adel NOFAL
The accumulation of iron in molten aluminium alloy scrap is one of the main concerns for the recycling and casting industries because it can lead to the formation of Fe rich intermetallic compounds which are detrimental to mechanical properties. Existing methods to reduce accumulated iron may be effective, but they all suffer from poor efficiency. Hence, if downgrading secondary aluminium to low q ... More
Presented by Dr. Jaime LAZARO-NEBREDA
Transverse cracking of continuously cast products has been encountered at almost every caster operation. Enormous efforts have been carried out in the past aiming at identifying the cause and reducing the problem, especially on steel grades with peritectic chemistries. So far, however, there is still no cost-effective solution with good trade-off for internal quality and productivity. In this stud ... More
Presented by Dr. Hongbin YIN
Additive manufacturing has been regarded as a highly potential method to produce metallic parts with complex geometry. Its basic process in fact is laser melting and the fast solidification afterward. Controlling such process or tailoring the solidification structure of the metallic samples fabricated via additive manufacturing is therefore the control of that fast solidification process. This is ... More
Presented by Prof. Jiang WANG
The aim of this talk is to present the evolution of the important concepts that led to the modelling of solidification, before the landmark paper by Tiller, Jackson, Rutter and Chalmers in 1953 on constitutional supercooling, and how they influenced our present-day models. Before the relevant research on solidification could start it required the development of essential basic concepts. Important ... More
Presented by Prof. Wilfried KURZ
Nozzle clogging at thin slab caster leads to quality issues and, in certain cases, losses in production. Clogging in and around nozzle and stopper rod is one of the major concerns for thin slab caster at Tata steel Jamshedpur plant which produces aluminium killed steel through BOF-LF route. Stopper Rise Index Model has been developed which forecasts the tendency for stopper rise, which is an indic ... More
Presented by Mr. Diti GARG
Camber in slabs is one of the major concerns in the Thin Slab Casting & Rolling process route. The camber in slab caused stuck up of slab in mill entry guide while taking slabs for rolling, resulting without order generation and sometimes chopping as well in the newly commissioned plant. A systematic data and metallurgical analysis has been done to find out the camber formation mechanism and relat ... More
Presented by Mr. ALOK KUMAR
The need for efficient and clean technology puts high demands on modern combustion engines, to compete in a market with alternative drive concepts. Downsizing and weight reduction require light alloys with superior thermo-mechanical properties for high temperature exposure. Cast Al-Si and Al-Cu alloys are competing last generation light materials to increase high temperature strength, creep-resist ... More
Presented by Dr. Michael SCHÖBEL
Experiments on the International Space Station (ISS) lead to the idea of a special growth mechanism in Al-rich Al-Ni melts. Previous analyses of dendrite growth velocity as a function of undercooling in these alloys showed anomalous behaviour, particularly a decreasing velocity for increasing undercoolings [1]. The experiments on the ISS reproduced the results obtained on earth but with an unprece ... More
Presented by Mr. Marcus REINARTZ
Microstructures, growth orientation and the room temperature mechanical properties of Mg-14.61Gd alloy were investigated by using directional solidification technology and CAFE simulation method under G=30K/mm and v=10-200μm/s. The experimental alloys were mainly consisted of primary α-Mg phase and (α-Mg+Mg5Gd) eutectic phase under all the growth conditions, which is consistent with the calcula ... More
Presented by Dr. Guangyu YANG
In hypoeutectic melts, the primary dendritic microstructures, a product of primary solidification, are of major importance when determining the final properties of cast components. Understanding the evolution of this primary microstructures during solidification, and the microsegregation changes associated during this process is critical, as they are in direct correlation to microstructural defect ... More
Presented by Mr. Juan Carlos HERNANDO
Inoculation with exogenous particles has been widely used in industry to grain refine various alloys during solidification. Among a series of Al-Ti-B based grain refiners developed for Al-alloys, the Al-5Ti-1B master alloy, which contains potent TiB2 particles for enhancing heterogeneous nucleation of α-Al grains, has been most widely used for decades. However, it has been reported that, in the p ... More
Presented by Dr. Yun WANG
Vigorous fluid flow appears in laser additive manufacturing (LAM) weld pools, with strong thermal gradients introducing buoyancy and Marangoni forces. Applying an external static magnetic field to this process will introduce two key additional effects. The first is electromagnetic damping that slows fluid motion across field lines, and the second is due to thermoelectric magnetohydrodynamics (TEMH ... More
Presented by Dr. Andrew KAO
Al-Mn alloys (3003) alloys are the preferred alloy series for brazed heat-exchangers for applications in the automotive industry. Cu, Si and other alloying elements are added in different amounts to improve alloy properties and achieve excellent thermal efficiency, high strength and corrosion resistance. Addition of Cu and Si results in longer solidification intervals which makes the alloys suscep ... More
Presented by Dr. Kjerstin ELLINGSEN
Al-Si alloys, which contains eutectic, are used in large quantities. Those are used not only like cast alloys but for base material of brazing technology as well. It is well known that too long Si lamellae can reduce the joining force of brazing, therefor it is necessary to produce finer eutectic structure. During manufacturing of brazing materials, the use of modifying agent (Na, Sr) is not alway ... More
Presented by Dr. Zsolt VERES
Grain refinement of metallic alloys is of critical importance to minimize the risk of solidification defects and obtain the desired mechanical properties. The effectiveness of grain refinement depends strongly on the interplay between potency of nucleant particles for heterogeneous nucleation and their ability for grain initiation. For a given alloy, the former is an inherent property of the nucle ... More
Presented by Alain JACOT
Magnetic fields have varieties of ubiquitous influence on nucleation and growth in solidification. As long as plenty of experimental phenomenon and results respectively have been revealed and retrieved, the mechanism of effect of magnetic fields on nucleation and growth in solidification keeps ambiguous. Not only thermodynamics mainly clarifies mechanism of growth qualitatively in solidification u ... More
Presented by Mr. Chenglin HUANG
Silicon is widely used in the industry of solar panels. During the manufacturing process, the molten silicon is solidified into ingots. These ingots are cut into very thin layers which are assembled into solar cells. It turns out that the solar cells efficiency depends on the solidification process and the final microstructure of the ingots. Several experimental studies of solidification showed ... More
Presented by Mr. Ahmed kaci BOUKELLAL
At present, the strength and toughness of Al alloys are still far from meeting the rapid development of the aerospace and automotive industries. Adding ceramic nanoparticles or increasing cooling rate can significantly refine the microstructure of Al alloys and improve the mechanical properties. In our work, an Al-TiC master alloy containing TiC nanoparticles was synthesized by combustion reaction ... More
Presented by Mr. Xiao LIU
In aluminium alloys, iron is a common impurity as it is unavoidably picked up in practice. The excessive Fe is strongly prone to form various intermetallic phases. These intermetallics are generally brittle and act as stress raisers to weaken the coherence with Al matrix. Consequently, the cast components are degraded in terms of the elongation. However, Fe addition in Al-Mg alloys may be benefici ... More
Presented by Dr. Shouxun JI
The formation of casting defects, including macrosegregation, shrinkage cavity, porosity, and inclusion, which resulting from the combined action of multi-physics filed, is a complex process. This process including the nucleation, growth, floating (or settling) of both inclusion and equiaxed crystals; growth and fragmentation of dendritic crystals; solidification shrinkage; solute redistribution a ... More
Presented by Dr. JUN LI
A method for detecting sticker breakouts in continuous casters is proposed based on extensive feature engineering and advanced analytical modelling. It is observed that the temperature patterns generated during a sticker breakout have a consistent signature, owing to the underlying physical processes involved. The aim of the present exercise is to capture this latent physical phenomenon in a relia ... More
Presented by Mr. Ranjay SINGH, Mr. Anurag BHATT
During solidification metallic alloys undergo a continuous transition from the liquid to the solid state. At first, solid dendrites growth and are free to move in the liquid matrix. In this case, the alloy can be considered as a suspension. As solidification progresses, interactions between dendrites occur and the mush develops shear strength due to dendrite entanglement. For higher solid fraction ... More
Presented by Dr. Gottfried LASCHET
A thermo-mechanical model of powder bed fusion by laser beam is developed by the finite element method at the macro-scale. This approach focuses on the part construction, in which a level-set framework is adopted to track first the interface between the constructed part and the non-exposed powder, and second, the interface between gas and the successive powder bed layers. The accounting for the no ... More
Presented by Dr. Yancheng ZHANG
Interest has recently emerged for the manufacture of aeronautical parts by Laser Beam Melting (LBM) additive process. Indeed, this energy efficient process can for instance be used to build complex geometries, which cannot be built with traditional processes. However, complex phenomena occur in the early stages of powder melting and track development: vaporisation phenomena influence laser-matter ... More
Presented by Mr. Alexis QUEVA
Sheet Mg products are a promising solution for a wide range of applications in the automotive sector, overcoming restrictions on green-house gas emission and meeting the continued push for light-weighting. In personal electronics applications, in addition to light-weighting, electro-magnetic shielding and damping capacities are of importance. The direct strip/sheet casting process brings a signif ... More
Presented by Dr. Xinliang YANG
A mesoscopic envelope model is used to numerically simulate the equiaxed solidification of an Al-20 wt$\%$Cu thin sample under isothermal and constant cooling rate conditions in the presence of gravity. The solute rejection from the grains to the melt yields composition gradients in the latter. This results in a non-uniform density of the melt which triggers the melt natural convection when gravit ... More
Presented by Dr. ANTONIO OLMEDILLA
The interaction between the capillarity and the thermal-solute-convection fields determines the microstructure evolution during solidification, which significantly influences the eventual mechanical properties of materials. However, to achieve the coupled thermal-solute-convection microstructure evolution with a realistic Lewis number (Le ~ 104) and Prandtl number (Pr ~ 10-2), the computing overhe ... More
Presented by Mr. Ang ZHANG
Tailored heterogeneous distributions of microstructural features enable extraordinary material performance in biological and physiological structures as trees, the aortic arch, human teeth and dinosaur skulls. In ductile iron, a heterogeneous distribution in size and morphology of graphite nodules and variations of the fractions of ferrite and pearlite are created during solidification, and varies ... More
Presented by Dr. Jakob OLOFSSON
A three-phase equiaxed solidification model where macroscale heat transfer and fluid flow are coupled with microscale nucleation and dendrite growth, is applied to the simulation of the macrosegregation in binary alloy solidification subjected to the electromagnetic stirring. The investigated experimental solidification case is conducted in a cavity which has a precise control of the thermal bound ... More
Presented by Mr. Tao WANG
Dendrites are ubiquitous structures that are central to setting material properties but the mechanism behind how dendrites grow is not fully understood. After x-ray synchrotron radiation experiments are performed, the dendritic growth of Al-12.6wt%Cu alloys is studied in 4-dimensions to track the evolution of the 3-dimensional structure as a function of time using novel x-ray tomography algorithms ... More
Presented by Ms. Kate ELDER
For liquid metal, heterogeneous nucleation is main channel towards the formation of solid crystal. Fine tuning of nucleation means an optimized solidification structure, and consequently promises tailored properties for application. There are a few extensively used industrial practices for nucleation tuning, as AlTiB catalyzed grain refining in Al alloys, silicon modification for AlSi alloys, sphe ... More
Presented by Dr. mingxu XIA
Frank in 1952 [1] already postulated that Icosahedral Short-Ranger Order (ISRO) in the liquid might explain the large undercoolings measured by Turnbull in fcc of hcp metals. ISRO was later confirmed by several observations such as the formation of quasicrystals or the atomic structure of their approximant intermetallic phases, neutron small angle scattering and atomistic simulations. In contrast ... More
Presented by Prof. Michel RAPPAZ
To pave the way for electrification, the automotive industry continues to adopt a light-weighting solution to improve vehicle range and reduce CO2 emissions. With the increasing application of aluminium and magnesium alloys within the vehicle, the near-net shape high pressure die casting process has rapidly become the preferred route to manufacturing structural components, due to its high producti ... More
Presented by Mr. Ewan LORDAN
High pressure die casting (HPDC) is a cost-effective and net-shaped manufacturing process for mass production of engineering components that require thin walls, complex shapes, high dimensional tolerance and excellent surface finish. However, the mechanical properties of HPDC Al components usually show a large variation, which prevents the use of HPDC components in safety-critical applications. To ... More
Presented by Dr. yijie ZHANG
Void is one of the main defects in titanium alloy castings, and hot isostatic pressing(HIP) is an effective method to eliminate this defect.In titanium alloy castings, the shape of real void is complex, and there are structures such as sharp corners and small passages which would lead to a large number of meshes and easily divergent calculation. Therefore, the application of numerical simulation t ... More
Presented by Mr. Qian XU
MATLAB is utilized to identify and locate detrimental oxide–sulfide stringers from the hot rolled plates. A method to estimate the inclusion phases of low carbon, aluminum-killed and calcium-treated steels is proposed. The inclusions are taken as a mixture of CaS, MnS, TiN and oxide (Al<sub>2</sub>O<sub>3</sub>-CaO-MgO) phases. The phase fractions and oxide phases composition are calculated fro ... More
Presented by Mr. Tuomas ALATARVAS
The presentation will highlight the recent developments in the world of Forged Special Steels and remelted steels (nickel alloys, stainless steel, alloy tool steel and alloy steel) as well as will give an overview about end-user demand and structures of these special steels and also summarize the actual status of installations (forging presses and remelting units) on a global scale. The speech wil ... More
Presented by Mr. Benedikt BLITZ
X-ray radioscopic studies have been performed to improve the understanding of the complex interrelation between melt flow and the evolution of dendritic structures during solidification of Ga-In alloys. Natural convection is caused by density variations within the solidifying alloys. Forced convection was produced by electromagnetic stirring. Within this work special interest was focused on dendri ... More
Presented by Dr. Natalia SHEVCHENKO