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Displaying 204 contributions out of 204
Type: Oral Presentation Session: Dendritic microstructure
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 Laszlo STURZ on 19 Jun 2019 at 15:00
Type: Oral Presentation Session: Dendritic microstructure
In this study, 3D flow fields, sump profiles and macrosegregation patterns are predicted for HDC slabs of an Al–4.5 wt.% Cu alloy. Numerical simulations are used to provide initial estimates of these features and the influence of slab geometry for a constant inlet configuration. In general, the heat conduction across the slab thickness controls the sump depth and general macrosegregation profile ... More
Presented by Mr. John COLEMAN on 20 Jun 2019 at 17:30
Type: Oral Presentation Session: Dendritic microstructure
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 Fatima MOTA on 18 Jun 2019 at 14:40
Type: Keynote Session: Dendritic microstructure
A 3D meso-scale discrete-element model has been developed to simulate fluid flow during dendritic solidification of steel. The model domain is a representative volume element consisting of a set of equiaxed dendritic grain envelopes along with extra-dendritic liquid channels, where the final grain shape is given by a Voronoi tessellation. Solidification of each grain is simulated via a volume ... More
Presented by Yi FENG on 19 Jun 2019 at 13:30
Type: Oral Presentation Session: Dendritic microstructure
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 Abdellah KHARICHA on 19 Jun 2019 at 14:40
Type: Highlight Session: Solidification processing
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 Wanqi JIE on 20 Jun 2019 at 16:10
Type: Oral Presentation Session: Continuous casting
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 Andrew SMITH on 18 Jun 2019 at 14:40
Type: Oral Presentation Session: Dendritic microstructure
Molecular dynamic simulations, ab initio (DFT) calculations and experimental evidence suggests that there is a liquid-solid transition region which may be characterised by an order parameter. In this interface region the order parameter is not observed to be symmetrical, rather it tends to be steep on the solid side and exponentially decreasing on the liquid side. The order parameter in phase fie ... More
Presented by Peter BOLLADA on 18 Jun 2019 at 16:50
Type: Oral Presentation Session: Solidification processing
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 Yun CHEN on 21 Jun 2019 at 12:10
Type: Oral Presentation Session: Thermomechanics & properties
Continuous casting is currently the main industrial process for steel production. Since long time, industries search for efficient simulation methods, by which macrosegregation and deformation induced cracks can be predicted. As a first step this requires achieving concurrent simulation of fluid flow and stress-strain. Therefore, a partitioned solution algorithm is developed for such simulatio ... More
Presented by SHAOJIE ZHANG on 19 Jun 2019 at 10:50
Type: Oral Presentation Session: Liquid metal processing
This paper summarizes the development of a computational fluid dynamics (CFD) model based on the commercial software package ANSYS-CFX, which has been used to examine the kinetics of dissolution of a single stationary Ti-N particle surrounded by moving liquid titanium. The model accounts for diffusional mass transport in the solid particle, the formation of a two-phase solid/liquid boundary la ... More
Presented by Prof. Steven COCKCROFT on 18 Jun 2019 at 10:50
Type: Highlight Session: Solidification processing
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 Juergen JAKUMEIT on 18 Jun 2019 at 16:10
Type: Oral Presentation Session: Iron and Steel processing
IDS (Inter-Dendritic Solidification) is a thermodynamic-kinetic software package that simulates phase changes, compound formation/dissolution, and solute distribution during solidification of steels as well as during their cooling/heating process after solidification. The software package also simulates solid-state phase transformations related to the austenite decomposition process at temperature ... More
Presented by Ville-Valtteri VISURI on 21 Jun 2019 at 12:10
Type: Oral Presentation Session: Thermomechanics & properties
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 cylinder blocks in these engines. Conventiona ... More
Presented by Farzaneh FARHANG MEHR on 19 Jun 2019 at 14:00
Type: Oral Presentation Session: Dendritic microstructure
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 Hieram NEUMANN-HEYME on 18 Jun 2019 at 16:30
Type: Oral Presentation Session: Solidification processing
Correct prediction of composition heterogeneities and grain structure across a steel ingot is critical in optimizing the industrial processing parameters for enhanced performance. The columnar to equiaxed transtion (CET) is a microstructural transition which is strictly controlled as it affects the mechanical properties of the final product along with the macrosegregation patterns. Larger equiax ... More
Presented by Savya SACHI on 20 Jun 2019 at 17:10
Type: Oral Presentation Session: Dendritic microstructure
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 Mohammed M'HAMDI on 20 Jun 2019 at 16:10
Type: Oral Presentation Session: Eutectic microstructure
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 Sabine BOTTIN-ROUSSEAU on 19 Jun 2019 at 14:00
Type: Oral Presentation Session: Peritectic growth
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 Rian DIPPENAAR on 20 Jun 2019 at 10:50
Type: Poster Session: Poster Session
Due to start-up and shut-down operations of engine, TiAl structural components usually 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 types of ... More
Presented by Li WEN on 18 Jun 2019 at 18:18
Type: Oral Presentation Session: Plenary Session
Thanks to the recent advance in high-performance computing, the range of application of atomistic simulation is rapidly expanding. We have performed large-scale molecular dynamics (MD) simulations of solidification process including nucleation from undercooled melt and grain growth in the system [1], and discussed heterogeneity in homogeneous nucleation [1] and decrease of the grain boundary mobil ... More
Presented by Yasushi SHIBUTA on 18 Jun 2019 at 09:25
Type: Highlight Session: Dendritic microstructure
Observations of melting crystallites in microgravity showed unusual shape changesas melting proceeded toward extinction. When re-analyzed in 2011, shape evolution data showedneedle-like crystallites becoming spheroids as they melted toward extinction, suggesting thatsome type of capillary phenomenon at solid-liquid interfaces was responsible for an energy releasecapable of spherodising p ... More
Presented by Martin GLICKSMAN on 18 Jun 2019 at 16:10
Type: Highlight Session: Additive manufacturing
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 Peter LEE on 20 Jun 2019 at 10:30
Type: Oral Presentation Session: Additive manufacturing
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 Abhishek G.S. on 20 Jun 2019 at 11:10
Type: Poster Session: Poster Session
The study is focused on the influence of solidification thermal parameters upon the evolution of the microstructure (either cells or dendrites) of an Al-3wt%Mg-1wt%Si ternary alloy. It is well known that the application properties of metallic alloys will greatly depend on the final morphology of the microstructure. As a consequence, various studies have been carried out in order to determine the r ... More
Presented by Nathalie MANGELINCK on 18 Jun 2019 at 18:19
Type: Poster Session: Poster Session
Time-resolved in situ tomography of dendritic growth in Fe–0.45 mass% C carbon steel was performed using synchrotron radiation X-rays at SPring-8 synchrotron radiation facility (Japan) with improvement of the image quality using a physics-based filter. The voxel size of the reconstructed image was approximately 6.5 μm × 6.5 μm × 6.5 μm, and the time resolution (duration of 360° rotatio ... More
Presented by Hideyuki YASUDA on 18 Jun 2019 at 18:09
Type: Poster Session: Poster Session
Computational process modelling 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 of the low pressure die casting (LPDC) process for automotive wheels is to quantify the heat transfer coefficients (H ... More
Presented by Anis Umi SAADAH BINTI OTHMAN on 20 Jun 2019 at 17:56
Type: Highlight Session: Iron and Steel processing
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 non-aesthetic effect on machined surfaces, while at higher level it is detrimental for mechanical properties of the components. Chunky ... More
Presented by Jacques LACAZE on 21 Jun 2019 at 10:30
Type: Oral Presentation Session: Intermetallics
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 Qiang DU on 20 Jun 2019 at 16:10
Type: Oral Presentation Session: Plenary Session
A casting process usually starts with a liquid alloy that solidifies on cooling. Forced and/or natural convection in the melt as well as stresses and deformations that occur from uneven cooling of the just solidified part can be described quite accurately. The challenging range is when the amount of solid increases so that melt flow becomes more and more difficult while solid starts to build up a ... More
Presented by Andreas LUDWIG on 20 Jun 2019 at 08:50
Type: Oral Presentation Session: Dendritic microstructure
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 Olga BUDENKOVA on 20 Jun 2019 at 14:00
Type: Oral Presentation Session: Iron and Steel processing
One technology that is often employed in continuous casting of high-carbon steel billets to minimize centre- (or macro) segregation is hard secondary cooling. Investigations unanimously show, that hard cooling significantly reduces macro-segregation, but a mechanism for the reduced segregation is rarely given. In this paper the solidification of high carbon tire cord grade C80D cast as a 150x1 ... More
Presented by Anthony Nicholas GRUNDY on 21 Jun 2019 at 11:50
Type: Oral Presentation Session: Iron and Steel processing
An experimental device conducts thermal analysis and volume change measurements in a single ceramic cup with cast iron quality as the variable. The recorded data are processed using specialized software. Experiments compare solidification patterns for white [WI], grey [GI] and ductile [DI] irons, to correlate the most important events between the cooling curves and contraction curves, to evaluate ... More
Presented by IULIAN RIPOSAN on 21 Jun 2019 at 10:50
Type: Poster Session: Poster Session
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 Christian BERNHARD on 20 Jun 2019 at 18:01
Type: Oral Presentation Session: Continuous casting
Maintaining competitiveness in steel manufacturing requires improving process efficiency and production volume whilst enhancing product quality and performance. This is particularly challenging for producing value-added advanced steel grades such as advanced high strength steels and electrical steels. These grades due to higher weight percentage of alloying elements cause difficulties in various s ... More
Presented by ARUNAVA SENGUPTA on 18 Jun 2019 at 15:00
Type: Poster Session: Poster Session
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 Julien ZOLLINGER on 18 Jun 2019 at 17:55
Type: Poster Session: Poster Session
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 Alexandre VIARDIN on 18 Jun 2019 at 17:56
Type: Oral Presentation Session: Thermomechanics & properties
The determination of pattern dimensions using simulation is an inefficient trial-anderror process that requires several design iterations. In this study, the finite element inverse elastoplastic analysis is utilized to calculate the pattern geometry in a single iteration for a plastically deformed body. A simplified casting system is simulated to demonstrate the feasibility of the inverse meth ... More
Presented by Prof. Christoph BECKERMANN on 19 Jun 2019 at 14:40
Type: Oral Presentation Session: Dendritic microstructure
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 Yun CHEN on 20 Jun 2019 at 11:10
Type: Highlight Session: Dendritic microstructure
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. Despite this, little direct evidence of such a fragmentation process usually survives in the as-solidified material. We report on the rapid solidification of the single phase, congruently melti ... More
Presented by Andrew MULLIS on 18 Jun 2019 at 10:30
Type: Oral Presentation Session: Solidification processing
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 for semiconductor production, with the consideration of weight and cost reduction. Several thick aluminum castings were manufactured using chill with temperature measurements. The casti ... More
Presented by In-Sung CHO on 20 Jun 2019 at 16:50
Type: Highlight Session: Liquid metal processing
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. The r ... More
Presented by Reinhold SCHNEIDER on 18 Jun 2019 at 10:30
Type: Oral Presentation Session: Iron and Steel processing
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 Manuel de Jesús CASTRO-ROMÁN on 21 Jun 2019 at 11:10
Type: Oral Presentation Session: Thermomechanics & properties
In this study, the pores in die-cast AlSiMgMn alloys were inspected and reconstructed with high resolution three-dimensional (3D) X-ray micro computed tomograpgy (μ-CT) technique. Finite element (FE) meshes were built with consideration of the pore actural morphorloges from the CT inspection. Based on dutile damage model, the FE simulation of tensile fracture of the alloys was carried out. The si ... More
Presented by Haidong ZHAO on 19 Jun 2019 at 11:50
Type: Oral Presentation Session: Dendritic microstructure
Within the framework of the ESA GRADECET project, experiments of directional solidi cation of cylindrical Ti-Al samples were conducted in hypergravity. The experiments were performed in a centrifuge with the apparent gravity (sum of centrifugal and terrestrial gravity) aligned along the cylinder centerline. 3D numerical simulations of aluminum macrosegregation in these samples are presented. A ... More
Presented by Martín Matías CISTERNAS FERNÁNDEZ on 20 Jun 2019 at 17:10
Type: Oral Presentation Session: Eutectic microstructure
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) experiments were performed using thin alloy samples with real-time observation. We identified two ma ... More
Presented by Prof. Melis SEREFOGLU on 19 Jun 2019 at 15:00
Type: Oral Presentation Session: Solidification processing
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 Shishira BHAGAVATH on 20 Jun 2019 at 16:30
Type: Oral Presentation Session: Dendritic microstructure
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 ... More
Presented by Stephan JÄGER on 20 Jun 2019 at 15:00
Type: Oral Presentation Session: Dendritic microstructure
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 Yuansheng YANG on 21 Jun 2019 at 12:10
Type: Oral Presentation Session: Nucleation and grain refinement
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 Feng WANG on 18 Jun 2019 at 10:50
Type: Poster Session: Poster Session
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 Yukimi OKA on 18 Jun 2019 at 18:07
Type: Keynote Session: Continuous casting
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 Christian BERNHARD on 18 Jun 2019 at 13:30
Type: Oral Presentation Session: Solidification processing
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 on 18 Jun 2019 at 16:30
Type: Oral Presentation Session: Dendritic microstructure
During casting, diffusion phenomena are often simplified by Lever-Rule or Gulliver-Scheil hypotheses, thus simplifying chemical diffusion to extreme configurations. The present work proposes an extension of the Tong-Beckermann microsegregation model to multi-component alloys while considering finite diffusion in liquid and solid phases plus the effect of tip undercooling of the columnar fro ... More
Presented by Vincent MAGUIN on 20 Jun 2019 at 14:40
Type: Poster Session: Poster Session
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 Mr. Gildas GUILLEMOT on 18 Jun 2019 at 17:51
Type: Oral Presentation Session: Dendritic microstructure
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 Shuangming LI on 18 Jun 2019 at 11:30
Type: Oral Presentation Session: Dendritic microstructure
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 Chuanjun LI on 21 Jun 2019 at 11:30
Type: Oral Presentation Session: Solidification processing
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 a homogeneous concentration along the sample axis. As stirring in samples of a certain length is difficult, homogenization by rapid solidification is very common. Hereby, the liquid sample is rapidly moved from ... More
Presented by Johann Peter MOGERITSCH on 18 Jun 2019 at 17:30
Type: Oral Presentation Session: Nucleation and grain refinement
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 Feng GAO on 18 Jun 2019 at 11:30
Type: Oral Presentation Session: Nucleation and grain refinement
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 sui ... More
Presented by Yuanding HUANG on 18 Jun 2019 at 11:10
Type: Oral Presentation Session: Nucleation and grain refinement
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 Hua MEN on 18 Jun 2019 at 15:20
Type: Oral Presentation Session: Intermetallics
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 Yan HUANG on 20 Jun 2019 at 15:20
Type: Oral Presentation Session: Peritectic growth
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 Janin EIKEN on 20 Jun 2019 at 11:30
Type: Poster Session: Poster Session
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 Samuel CLARK on 20 Jun 2019 at 18:14
Type: Oral Presentation Session: Dendritic microstructure
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 Virkeshwar KUMAR on 18 Jun 2019 at 14:00
Type: Poster Session: Poster Session
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. Qiang WANG on 20 Jun 2019 at 18:22
Type: Keynote Session: Eutectic microstructure
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 Mathis PLAPP on 19 Jun 2019 at 13:30
Type: Oral Presentation Session: Nucleation and grain refinement
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 regions in as-cast Al-based and Au-based fcc alloys, Kurtuldu et al. have shown recently that a so-ca ... More
Presented by Julien ZOLLINGER on 18 Jun 2019 at 14:00
Type: Oral Presentation Session: Liquid metal processing
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 Ebrahim KARIMI SIBAKI on 18 Jun 2019 at 11:10
Type: Poster Session: Poster Session
During continuous casting of steel, the strand is exposed to severe thermal and mechanical stresses. These may trigger formation and growth of cracks, which deteriorate the slab properties. Particularly, at temperatures in the region of the second ductility trough, deformation can become critical. A low ductility level is often observed in a temperature range of 600°C to 1200°C, where the bendin ... More
Presented by Jakob SIX on 20 Jun 2019 at 18:21
Type: Highlight Session: Dendritic microstructure
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 Zhongming REN on 21 Jun 2019 at 10:30
Type: Oral Presentation Session: Continuous casting
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 Carl SLATER on 18 Jun 2019 at 14:00
Type: Oral Presentation Session: Dendritic microstructure
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 JUN WANG on 21 Jun 2019 at 11:50
Type: Poster Session: Poster Session
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 Prof. abdellah KHARICHA on 18 Jun 2019 at 18:10
Type: Oral Presentation Session: Thermomechanics & properties
Chills are used in the production of metal 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 Charles MONROE on 19 Jun 2019 at 15:20
Type: Oral Presentation Session: Eutectic microstructure
Directional solidification is a favored process to manufacture homogeneous microstructures which lead to macroscopically unique properties for a material. The dependence of the spacing and type of the arising microstructure from the solidification velocity for constant velocities is extensively investigated. However the effect of changes in the solidification velocity on the resulting microstr ... More
Presented by Johannes HÖTZER on 19 Jun 2019 at 14:20
Type: Oral Presentation Session: Liquid metal processing
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 T.O content and S content decreased because of cleanliness improvement of ESR process. Transv ... More
Presented by Qiang WANG on 18 Jun 2019 at 11:50
Type: Highlight Session: Peritectic growth
For a long time, the γ phase in metallic alloys has seemed to be produced through a peritectic reaction between the δ and liquid phases. However, direct observations have shown that a massive-like transformation, in which the δ phase transforms into the γ phase in the solid state, is dominant during or after solidification of the δ phase in carbon steels. To characterize such massive-like ... More
Presented by Hideyuki YASUDA on 20 Jun 2019 at 10:30
Type: Oral Presentation Session: Plenary Session
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 Nathalie MANGELINCK-NOËL on 19 Jun 2019 at 08:15
Type: Oral Presentation Session: Plenary Session
For the simulation of phase transformations and thermal problems in general, a set of input data is required that for the majority of alloys is unavailable with sufficient accuracy. ”Remedies” are to use data of the pure major alloying element, or use constant values that were measured at room temperature, neglecting their temperature dependence. The effort to gain temperature dependent data f ... More
Presented by Markus RETTENMAYR on 21 Jun 2019 at 08:50
Type: Oral Presentation Session: Dendritic microstructure
Kinetics of crystal growth in undercooled melts is analyzed by methods of theoretical modeling. Special attention is paid to rapid growth regimes occurring at deep undercoolings at which non-linearity in crystal velocity appears. A traveling wave solution of the phase eld model (PFM) derived from the fast transitions theory is used for a quantitative description of the crystal growth kinetics ... More
Presented by Peter GALENKO on 18 Jun 2019 at 17:30
Type: Oral Presentation Session: Dendritic microstructure
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 Eisuke MIYOSHI on 19 Jun 2019 at 11:30
Type: Poster Session: Poster Session
Laser Beam Melting (LBM) processes benefit from significant progress in recent years. Currently, manufacturing of ceramic parts for applications at high temperature in aeronautical industries can be planned. However, understanding of defect formation is required in order to optimize manufacturing strategy. In this work, level-set modelling is proposed to simulate tracks development during LBM proc ... More
Presented by Gildas GUILLEMOT on 20 Jun 2019 at 18:04
Type: Oral Presentation Session: Additive manufacturing
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 Junjie LI on 20 Jun 2019 at 15:20
Type: Oral Presentation Session: Plenary Session
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 Dianzhong LI on 20 Jun 2019 at 09:25
Type: Oral Presentation Session: Nucleation and grain refinement
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 particle 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 wo ... More
Presented by Julien ZOLLINGER on 18 Jun 2019 at 17:30
Type: Highlight Session: Dendritic microstructure
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 Tadej DOBRAVEC on 19 Jun 2019 at 10:30
Type: Oral Presentation Session: Dendritic microstructure
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 Alexandre VIARDIN on 19 Jun 2019 at 14:20
Type: Oral Presentation Session: Plenary Session
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 Carolin KÖRNER on 20 Jun 2019 at 08:15
Type: Poster Session: Poster Session
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 Jaehoon LEE on 18 Jun 2019 at 18:06
Type: Oral Presentation Session: Eutectic microstructure
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 Isaac CHANG on 19 Jun 2019 at 11:10
Type: Keynote Session: Thermomechanics & properties
Comprehensive thermomechanical casting simulations offer the opportunity to increase the dimensional accuracy of cast parts. These simulations require accurate material properties, which are delicate to measure experimentally in the mushy zone. These properties are often specified only as function of the temperature, neglecting the impact of the non-equilibrium character of the evolving microstruc ... More
Presented by Gottfried LASCHET on 19 Jun 2019 at 13:30
Type: Oral Presentation Session: Solidification processing
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 or across the liquidus line to ... More
Presented by Suwaree CHANKITMUNKONG on 18 Jun 2019 at 17:10
Type: Oral Presentation Session: Dendritic microstructure
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 Tong Zhao GONG on 18 Jun 2019 at 15:00
Type: Poster Session: Poster Session
This work focuses on bimetallic casting between A356 alloy melt and profiles of AA6xxx wrought aluminum alloys through a gravity casting process, with the aim to improve the component’s mechanical properties. However, combining two aluminum alloys is difficult due to the stable aluminum oxide present on the surface of the aluminum inserts and the advancing liquid melt front. The oxide layer stro ... More
Presented by Aina Opsal BAKKE on 20 Jun 2019 at 18:15
Type: Poster Session: Poster Session
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 Oriane SENNINGER on 18 Jun 2019 at 17:58
Type: Oral Presentation Session: Additive manufacturing
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 David BROWNE on 20 Jun 2019 at 14:40
Type: Oral Presentation Session: Dendritic microstructure
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 YVES DU TERRAIL COUVAT on 21 Jun 2019 at 10:50
Type: Poster Session: Poster Session
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 Yasushi SHIBUTA on 20 Jun 2019 at 18:08
Type: Poster Session: Poster Session
Since it is not straightforward to directly observe nucleation at the initial stage of solidification in experiments, investigation from computational approach is strongly desired. In this study, influence of grain refiner in heterogeneous nucleation of undercooled Al melt is investigated by molecular dynamics calculations. Particularly, we focus temperature, size of the refiner, and anisotrop ... More
Presented by Takuya FUJINAGA on 20 Jun 2019 at 18:05
Type: Poster Session: Poster Session
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 Shinji SAKANE on 18 Jun 2019 at 18:05
Type: Highlight Session: Dendritic microstructure
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 Tomohiro TAKAKI on 20 Jun 2019 at 10:30
Type: Oral Presentation Session: Dendritic microstructure
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 Jinglian DU on 19 Jun 2019 at 10:50
Type: Oral Presentation Session: Plenary Session
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 Alain KARMA on 19 Jun 2019 at 08:50
Type: Oral Presentation Session: Dendritic microstructure
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 Damien TOURRET on 19 Jun 2019 at 14:00
Type: Poster Session: Poster Session
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 Yi QIU on 18 Jun 2019 at 18:11
Type: Keynote Session: Intermetallics
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 Chris GOURLAY on 20 Jun 2019 at 13:30
Type: Oral Presentation Session: Intermetallics
The current work, describes a numerical methodology to obtain deeper understanding of the kinetics of solidification and the dynamics of Al melt infiltration into porous iron preforms, in order to develop a near net shape process for a new class of highly advanced ductile and fine grained Fe-Al intermetallic. Investigations on macroscale simulations revealed that certain pressure and wetting condi ... More
Presented by Ralf BERGER on 20 Jun 2019 at 17:10
Type: Poster Session: Poster Session
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 Bruno LEBON on 20 Jun 2019 at 18:09
Session: Poster Session
The high pressure die casting process is extensively used to manufacture light metal parts with high productivity. A major drawback of the process is the relatively high variability in mechanical properties and poor repeatability between casting cycles, limiting the achievement of weight reduction through lighter design. Although it has been established that mechanical properties are adversely ... More
Presented by Alain JACOT on 20 Jun 2019 at 18:10
Type: Oral Presentation Session: Dendritic microstructure
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 Haijie ZHANG on 21 Jun 2019 at 11:10
Type: Oral Presentation Session: Nucleation and grain refinement
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 David STJOHN on 18 Jun 2019 at 16:30
Type: Poster Session: Poster Session
Asymmetric flow of the molten steel in a continuous slab casting mold may be detrimental to the quality of the solidified end product. Depending on the severity of the biased flow, local mold powder entrainment, non-homogeneous solidification around the perimeter of the initial shell or non-optimal inclusion seclusion may occur. In particular, nozzle clogging in the last slabs before an SEN exchan ... More
Presented by Martin SEDÉN on 20 Jun 2019 at 18:00
Type: Oral Presentation Session: Liquid metal processing
This paper aims to obtain fundamental information on chemical homogenisation process of liquid steel with alloy additions in the bloom 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 work basic and propo ... More
Presented by Adam CWUDZINSKI on 18 Jun 2019 at 11:30
Type: Oral Presentation Session: Dendritic microstructure
In this study, a numerical model was developed, and direct simulations were performed to predict solidification grain structures and macrosegregation based on a threedimensional cellular automaton finite difference (CAFD) method coupled with flow calculation of natural convection and shrinkage flow. First, to evaluate the model coupled with natural convention, simulations of unidirectional sol ... More
Presented by Yukinobu NATSUME on 20 Jun 2019 at 10:50
Type: Oral Presentation Session: Plenary Session
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 Sylvain DEVILLE on 21 Jun 2019 at 08:15
Type: Oral Presentation Session: Solidification processing
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 interact with meso and macro events, is one of awkward challeng ... More
Presented by Amir HORR on 21 Jun 2019 at 11:30
Type: Oral Presentation Session: Thermomechanics & properties
As it is known from literature, the metals tend to follow a viscoplastic law at high temperatures. Thereby, based on the authors’ previous developments to simulate the behavior of the equiaxed crystals packed bed, a viscoplastic stress model is applied to the thin slab casting process. The model is reduced to the single phase mixture formulation for faster and robust simulations. In this idea, t ... More
Presented by Alexander VAKHRUSHEV on 19 Jun 2019 at 14:20
Type: Poster Session: Poster Session
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 Dr. JUN LI on 18 Jun 2019 at 18:12
Type: Poster Session: Poster Session
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, grain growth leads to a gradual increase of solid fraction, so that a coherent solid network forms. Depending on the process condition, this solid network might be subjected to compression within the gap between the two r ... More
Presented by Andreas LUDWIG
Type: Oral Presentation Session: Thermomechanics & properties
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 Johan JANSSON on 19 Jun 2019 at 15:00
Type: Oral Presentation Session: Solidification processing
Advanced numerical simulation models for continuous casting of steel were developed in Finland by Casim Consulting and Aalto University in cooperation with the University of Oulu and the steel industry. The aim was to develop models that are scientifically rigorous, but also computationally fast enough to be used in online applications. The models developed are a transient three-dimensional heat t ... More
Presented by Ville-Valtteri VISURI on 21 Jun 2019 at 10:50
Type: Oral Presentation Session: Solidification processing
Ultrasonic processing (USP) during direct-chill (DC) casting of light metal 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) a limited volume that can be processed by a single ultrasonic source. We suggest moving the l ... More
Presented by Tungky SUBROTO on 18 Jun 2019 at 16:50
Type: Oral Presentation Session: Peritectic growth
Retained free energy drives the transformation from metastable to stable phase during double recalescence of steel alloys. Statistical methods were used to identify the mechanism controlling cluster growth based on the principle of microstructural reversibility. Application of the coefficient of determination during optimization procedures showed that an extrinsic mechanism controls nucleation an ... More
Presented by Douglas M. MATSON on 20 Jun 2019 at 11:50
Type: Oral Presentation Session: Additive manufacturing
Selective Laser Melting (SLM), the most popular metal additive manufacturing (AM) process, is well suited for making complicated parts which are difficult to manufacture by conventional manufacturing techniques. Currently, the main bottlenecks inhibiting the usage of the Selective Laser Melting (SLM) parts include the problems, such as porosity, low resolution, low surface finish quality and low b ... More
Presented by Arvind KUMAR on 20 Jun 2019 at 14:20
Type: Poster Session: Poster Session
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 Yasumasa MITSUYAMA on 18 Jun 2019 at 18:14
Type: Oral Presentation Session: Plenary Session
Directional solidification of eutectics has been extensively studied in systems which display regular coupled growth with the solid-liquid interfaces being non-faceted. The solid-solid phase boundaries however may be locked or loosely attached to planes with a low energy configuration being associated with a characteristic crystallographic orientation relationship (OR). The phase boundary energy l ... More
Presented by Ulrike HECHT on 19 Jun 2019 at 09:25
Type: Oral Presentation Session: Nucleation and grain refinement
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 Jincheng WANG on 18 Jun 2019 at 14:40
Type: Oral Presentation Session: Additive manufacturing
Understanding the dynamic evolution of primary 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 properties of additive manufactured products. In this work, a multi-scale computational framework that couples FEM and a developed quantitative phase field method is empl ... More
Presented by Wang ZHENG on 20 Jun 2019 at 15:00
Type: Oral Presentation Session: Dendritic microstructure
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 Haifeng WANG on 18 Jun 2019 at 17:10
Type: Poster Session: Poster Session
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 Takahisa KINOSHITA on 18 Jun 2019 at 18:08
Type: Poster Session: Poster Session
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 Kaveh DARGAHI NOUBARY on 18 Jun 2019 at 17:50
Type: Oral Presentation Session: Eutectic microstructure
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 Marco SEIZ on 19 Jun 2019 at 11:50
Type: Oral Presentation Session: Peritectic growth
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 Dasith Deshan LIYANAGE on 20 Jun 2019 at 11:10
Type: Poster Session: Poster Session
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 Geunwoo KIM on 18 Jun 2019 at 18:04
Type: Poster Session: Poster Session
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 Michael KELLNER on 18 Jun 2019 at 17:52
Type: Oral Presentation Session: Eutectic microstructure
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 Amber GENAU on 19 Jun 2019 at 10:50
Type: Oral Presentation Session: Intermetallics
The carbide precipitation nature of an automobile gear material, i.e. Fe-C-Mn-Si-Cr-Mo alloy, during carburization and element addition process are investigated through PE+PA+LR prediction. Results show that, carburization process greatly increases the amount of cementite as well as the hardness index at the surface part. Besides, the addition of Ti and V helps to formation of TiC and (V,Mo)C carb ... More
Presented by Hongwei ZHANG on 20 Jun 2019 at 16:30
Type: Oral Presentation Session: Dendritic microstructure
The control of the carbon macrosegregation level in steel ingots is important for the structural integrity of the nal component. During solidi cation, the fragmentation of the columnar dendrites is an important source of equiaxed grains, and has a large in uence on the macrosegregation and the grain structure. The goal of this study is to show that a numerical model that takes into account f ... More
Presented by Benjamin GERIN on 20 Jun 2019 at 16:30
Type: Highlight Session: Solidification processing
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 Alan A. LUO on 21 Jun 2019 at 10:30
Type: Oral Presentation Session: Nucleation and grain refinement
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 Changming FANG on 18 Jun 2019 at 15:00
Type: Oral Presentation Session: Dendritic microstructure
Under a NASA (National Aeronautics and Space Agency)-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 MICAST2-12) were directionally solidified at growth speeds varying from 10 to 50 μm s-1 aboard the Inte ... More
Presented by Prof. Surendra TEWARI on 18 Jun 2019 at 11:10
Type: Oral Presentation Session: Continuous casting
The ongoing RFCS project SUPPORT-CAST is aimed at finding optimal casting parameters and cooling rates to improve product quality based on high-resolution visualization topography scanning in combination with advanced numerical modelling. Surface scanning is performed by a blue laser sensor adapted to withstand temperatures up to 1200°C and capable of resolutions up to 30 microns. This enables de ... More
Presented by Pavel E. RAMIREZ LOPEZ on 18 Jun 2019 at 15:20
Type: Poster
The ongoing RFCS project SUPPORT-CAST is aimed at finding optimal casting parameters and cooling rates to improve product quality based on high-resolution visualization topography scanning in combination with advanced numerical modelling. Surface scanning is performed by a blue laser sensor adapted to withstand temperatures up to 1200°C and capable of resolutions up to 30 microns. This enables de ... More
Presented by Pavel E. RAMIREZ LOPEZ
Type: Oral Presentation Session: Intermetallics
This paper reports on the development of Solidification Continuous Cooling Transformation diagrams that relate 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 and phase diagra ... More
Presented by Hani HENEIN on 20 Jun 2019 at 14:20
Type: Oral Presentation Session: Intermetallics
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 Biao CAI
Type: Oral Presentation Session: Eutectic microstructure
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 Lina JIA on 19 Jun 2019 at 15:20
Type: Poster Session: Poster Session
Near eutectic Al-Cu droplets 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 samples revealed two distinct zones of different structural morphologies: An undulated eutectic morphology developed during recalescence following the single grain nucleation and a regular ... More
Presented by Hani HENEIN on 18 Jun 2019 at 18:01
Type: Oral Presentation Session: Intermetallics
This study aims in combining the material properties and numerical modelling techniques through practical application to provide understanding of surface edge cracking caused by V(C,N) precipitation to enhance the yield of the continuous bloom caster at ArcelorMittal Duisburg. The investigation for this work is carried out on three different micro-alloyed steel grades; one of them being the most c ... More
Presented by Esra ERDEM HORNAUER on 20 Jun 2019 at 15:00
Type: Highlight Session: Nucleation and grain refinement
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 Zhongyun FAN on 18 Jun 2019 at 10:30
Type: Oral Presentation Session: Nucleation and grain refinement
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 Yijiang XU on 18 Jun 2019 at 17:10
Type: Highlight Session: Nucleation and grain refinement
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 Yanjun LI, Lars ARNBERG on 18 Jun 2019 at 16:10
Type: Highlight Session: Eutectic microstructure
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 Silvere AKAMATSU on 19 Jun 2019 at 10:30
Type: Oral Presentation Session: Eutectic microstructure
Eutectic alloys are self-organising composite materials with a wide variety of microstructural features. Size, shape, distribution, and orientation of these features can be modified by process parameters (temperature gradient, velocity of interface) as well as material parameters (volume fractions, anisotropy of interfacial energies, diffusivities, impurity nature and its percentage etc.). The obj ... More
Presented by Kiran ARAMANDA SHANMUKHA on 19 Jun 2019 at 14:40
Session: Poster Session
It has been reported that native MgO particles in Mg alloy melts can act as heterogeneous nucleation substrates such that grain refinement of Mg alloys is achieved. A recent study showed the addition of Ca, combined with the native MgO particles, significantly improves grain refinement of Mg and its alloys. However, the mechanism underlying the grain refining phenomenon is not well understood due ... More
Presented by Prof. Zhongyun FAN on 20 Jun 2019 at 18:13
Type: Poster Session: Poster Session
Semi-grand canonical Monte Carlo (SGCMC) simulations are performed to derive thermodynamic properties of binary alloy from atomistic-based simulations. Particularly, solidus and liquidus compositions are directly derived for Fe-Cr alloy described by two different EAM potentials. Although the SGCMC simulation can derive relationship between the free energy and composition at any temperature straigh ... More
Presented by Ueno KENSHO on 18 Jun 2019 at 18:03
Type: Oral Presentation Session: Dendritic microstructure
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 Jean-Marc DEBIERRE on 19 Jun 2019 at 11:10
Type: Oral Presentation Session: Thermomechanics & properties
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-Zn Al). Both of these groups ... More
Presented by Witold K. KRAJEWSKI on 19 Jun 2019 at 11:30
Type: Oral Presentation Session: Solidification processing
Numerical simulation of casting filling process with complex shape is time-consuming. Compared with the traditional SOLA-VOF method, the lattice Boltzmann method (LBM) calculates the pressure field by particle distribution functions instead of the correction of the velocity and pressure fields, which greatly simplifies the calculation process. In addition, the LBM provides a flexible approach whic ... More
Presented by Yongjia ZHANG on 21 Jun 2019 at 11:50
Type: Keynote Session: Dendritic microstructure
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 Christoph BECKERMANN on 20 Jun 2019 at 13:30
Type: Poster Session: Poster Session
**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 Prof. Jiang WANG on 20 Jun 2019 at 17:54
Type: Oral Presentation Session: Solidification processing
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 Jianxin ZHOU on 21 Jun 2019 at 11:10
Type: Oral Presentation Session: Thermomechanics & properties
The grain boundary groove method has been successfully used to measure solid-liquid interfacial energies, σSL, experimentally for binary eutectic and peritectic systems, multi-component systems as well as pure materials and for opaque 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 prep ... More
Presented by Elif YILMAZ on 19 Jun 2019 at 11:10
Type: Poster Session: Poster Session
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 Begoña SANTILLANA on 20 Jun 2019 at 17:53
Type: Oral Presentation Session: Intermetallics
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 Kou HONGCHAO on 20 Jun 2019 at 16:50
Type: Oral Presentation Session: Dendritic microstructure
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 Qing CAI on 18 Jun 2019 at 11:50
Type: Poster Session: Poster Session
Solidification cracking is an important issue during welding, casting and some of the additive manufacturing process. In order to illuminate the failure mechanisms, solidification cracking during arc welding of steel are investigated in situ with high-speed, high energy, synchrotron X-ray radiography approach. Analysis of the in situ radiography sequence revealed the solidification cracking in ... More
Presented by Jun LI on 18 Jun 2019 at 18:16
Type: Oral Presentation Session: Additive manufacturing
A set of single track laser melting experiments was performed in a selective laser melting (SLM). The tracks were done on an Inconel 718 plate with various laser scan velocities at a constant laser power of 150 W. The geometries of the molten pool (MP), as well as the solidified dendrite structures, i.e., primary and secondary dendrite arm spacing (PDAS and SDAS), in the cross sections of the ... More
Presented by Yuze LI on 20 Jun 2019 at 11:30
Type: Oral Presentation Session: Dendritic microstructure
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 on 19 Jun 2019 at 11:50
Type: Poster Session: Poster Session
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 Moritz EICKHOFF on 18 Jun 2019 at 17:57
Type: Poster Session: Poster Session
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 Gonzalo ALVAREZ DE TOLEDO on 20 Jun 2019 at 18:17
Type: Oral Presentation Session: Additive manufacturing
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. Andrew DOUGLAS on 20 Jun 2019 at 10:50
Type: Poster Session: Poster Session
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 Can HUANG on 18 Jun 2019 at 17:54
Type: Oral Presentation Session: Intermetallics
The solidification path and the σ-phase precipitation mechanism of UNS S31254 alloy were studied on the basis of directional solidified experiments accompanied by scanning electron microscopy observations and energy dispersive X-ray a nalysis. The resulting temperatures of solidification paths and phase transformation were compared with Gulliver-Scheil and equilibrium calculations predicted using ... More
Presented by Raphaël MARIN on 20 Jun 2019 at 14:40
Session: Poster Session
The accumulation of iron in molten aluminium is one of the main concerns for the recycling and casting industries because it leads to the formation of undesirable Fe-rich intermetallic compounds which are detrimental to mechanical properties. Many methods have been developed in the past to reduce the iron accumulated in molten aluminium scrap, but they all suffer from poor efficiency. Hence, a mor ... More
Presented by Prof. Zhongyun FAN on 20 Jun 2019 at 18:12
Type: Oral Presentation Session: Continuous casting
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 Hongbin YIN on 18 Jun 2019 at 14:20
Type: Oral Presentation Session: Additive manufacturing
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 Jiang WANG on 20 Jun 2019 at 11:50
Type: Oral Presentation Session: Plenary Session
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 Wilfried KURZ on 18 Jun 2019 at 08:50
Type: Highlight Session: Thermomechanics & properties
The need for efficient and clean solutions, due to the increasing current environmental regulations puts extra pressure on new combustion engine development, to compete in a market with alternative driving concepts. Downsizing and weight reduction can reduce the engine emission and efficiency, but require light alloys with superior thermo-mechanical properties for high temperature exposure to ... More
Presented by Michael SCHÖBEL on 19 Jun 2019 at 10:30
Type: Oral Presentation Session: Dendritic microstructure
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 Marcus REINARTZ on 18 Jun 2019 at 10:50
Type: Poster Session: Poster Session
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 Guangyu YANG on 18 Jun 2019 at 18:02
Type: Oral Presentation Session: Nucleation and grain refinement
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 Yun WANG on 18 Jun 2019 at 14:20
Type: Oral Presentation Session: Solidification processing
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 Kjerstin ELLINGSEN on 20 Jun 2019 at 17:30
Type: Oral Presentation Session: Eutectic microstructure
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 Zsolt VERES on 19 Jun 2019 at 11:30
Type: Oral Presentation Session: Dendritic microstructure
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 on 20 Jun 2019 at 11:30
Type: Poster Session: Poster Session
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 Prof. Jiang WANG on 18 Jun 2019 at 17:53
Type: Poster Session: Poster Session
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. Jean-Marc DEBIERRE on 18 Jun 2019 at 17:59
Type: Oral Presentation Session: Intermetallics
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 Fe-rich intermetallics are generally brittle and act as stress raisers to weaken the coherence with Al matrix, therefore decreasing elongation. However, Fe addition in Al-Mg alloys may be beneficial because of the improvement ... More
Presented by Shouxun JI on 20 Jun 2019 at 14:00
Type: Keynote Session: Nucleation and grain refinement
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 Michel RAPPAZ on 18 Jun 2019 at 13:30
Type: Oral Presentation Session: Dendritic microstructure
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 JUN LI on 20 Jun 2019 at 16:50
Type: Poster Session: Poster Session
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 Ranjay SINGH, Anurag BHATT on 20 Jun 2019 at 17:57
Type: Keynote Session: Additive manufacturing
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 Yancheng ZHANG on 20 Jun 2019 at 13:30
Type: Oral Presentation Session: Additive manufacturing
Interest has recently emerged for the manufacture of aeronautical parts by Laser Beam Melting (LBM) additive process. This energy efficient process can for instance be used to build complex geometries, which cannot be made with traditional processes. However, complex phenomena occur during powder melting and track development : vaporisation phenomena influence laser-matter interaction by creating ... More
Presented by Alexis QUEVA on 20 Jun 2019 at 14:00
Type: Oral Presentation Session: Dendritic microstructure
A 3D mesoscopic envelope model is used to numerically simulate the experimental X-ray observations of the equiaxed dendritic isothermal solidification of a thin sample of Al-20 wt%Cu alloy including the natural convection flow. Several four-grain simulations are run to investigate the effect of the convection, of the grain position, and of the grain rotation on the tip growth kinetics of one of ... More
Presented by ANTONIO OLMEDILLA on 19 Jun 2019 at 15:20
Type: Oral Presentation Session: Dendritic microstructure
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 Ang ZHANG on 20 Jun 2019 at 11:50
Type: Oral Presentation Session: Iron and Steel processing
Tailored heterogeneous distributions of microstructural features enable extraordinary material performance in biological and physiological structures such 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, a ... More
Presented by Jakob OLOFSSON on 21 Jun 2019 at 11:30
Type: Oral Presentation Session: Dendritic microstructure
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 good control of the thermal boundary ... More
Presented by Tao WANG on 20 Jun 2019 at 14:20
Type: Oral Presentation Session: Dendritic microstructure
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 Kate ELDER on 18 Jun 2019 at 14:20
Type: Oral Presentation Session: Nucleation and grain refinement
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 Mingxu XIA on 18 Jun 2019 at 16:50
Type: Oral Presentation Session: Plenary Session
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. Only through three-dimensional m ... More
Presented by Peter VOORHEES on 21 Jun 2019 at 09:25
Type: Poster Session: Poster Session
Hot isostatic pressing(HIP) is an effective method to eliminate the shrinkage in castings. The morphology of shrinkage is complex, and there are structures such as sharp corners and small passages which would lead to a large number of elements and easily divergent calculation results. Therefore, the application of numerical simulation in HIP is limited. To solve the non-convergence problem, the re ... More
Presented by Qian XU on 20 Jun 2019 at 18:19
Type: Poster Session: Poster Session
The targets of this study were to determine the effect of vertical location and the composition of inclusions to the occurrence of oxide–sulfide stringers, and to determine the calcium aluminate phases most prone to form stringers during hot rolling of aluminium killed, calcium treated steel. The phases present in the inclusions have a significant effect on the deformation of inclusions during h ... More
Presented by Tuomas ALATARVAS on 20 Jun 2019 at 17:55
Type: Keynote Session: Dendritic microstructure
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 Natalia SHEVCHENKO on 18 Jun 2019 at 13:30