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Guodong Wang - One of the best experts on this subject based on the ideXlab platform.
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comparison of cracking sensitivity between high permeability 1 5 wt si steel and 6 5 wt si steel in Mushy Zone
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Yuanxiang Zhang, G. Yuan, Xiaoming Zhang, J.h. Zhao, Guodong WangAbstract:Abstract Twin-roll thin strip casting process (SC) has been utilized in laboratory to fabricate typical high-permeability electrical steel (HPES) such as 1.5 wt% Si and 6.5 wt% Si steel with ideal crystallographic orientation and excellent permeability after a series of heat treatments. Whereas, there exists a problem associated to the cracking sensitivity in high temperature Mushy Zone, which further restricts the industrial application of SC to produce HPES. Mechanical behavior of 1.5 wt% Si and 6.5 wt% Si steels in high temperature Mushy Zone were comparatively studied by Gleeble-3800 physical simulation system under strain rate 3 s−1, systematically. The high temperature brittle region composed of zero strength temperature (ZST) and zero ductility temperature (ZDT) in the Mushy Zone were quantitatively determined, and the critical strain threshold associated to hot crack initiation in the brittle region were further evaluated following empirical model proposed by Y Won. Results show that the tensile strength and fracture ductility in the Mushy Zone are both closely associated with the varying volume fraction of network-shaped structure during solidification, and are decreased with decreasing solid fraction concerning studied 1.5 wt% Si and 6.5 wt% Si steels. The high temperature brittle region corresponding to the studied 1.5 wt% Si and 6.5 wt% Si steels in Mushy Zone are separately confirmed to be 1459 ~ 1465℃ and 1390 ~ 1427℃, and the thresholds of critical strain for hot cracks initiation in high temperature brittle region are calculated to be ~ 1.18% and ~ 0.24%, respectively. Considering from perspective of width of high temperature brittle region and critical strain threshold for hot crack initiation, the cracking sensitivity of 6.5 wt% Si steel in the Mushy Zone is more serious compared to 1.5 wt% Si steel.
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Comparison of Cracking Sensitivity Between High-permeability 1.5 wt.% Si Steel and 6.5 wt.% Si Steel in Mushy Zone
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Hu Wei, Zhang Yuanxiang, G. Yuan, Xiaoming Zhang, J.h. Zhao, Guodong WangAbstract:Abstract Twin-roll thin strip casting process (SC) has been utilized in laboratory to fabricate typical high-permeability electrical steel (HPES) such as 1.5 wt% Si and 6.5 wt% Si steel with ideal crystallographic orientation and excellent permeability after a series of heat treatments. Whereas, there exists a problem associated to the cracking sensitivity in high temperature Mushy Zone, which further restricts the industrial application of SC to produce HPES. Mechanical behavior of 1.5 wt% Si and 6.5 wt% Si steels in high temperature Mushy Zone were comparatively studied by Gleeble-3800 physical simulation system under strain rate 3 s−1, systematically. The high temperature brittle region composed of zero strength temperature (ZST) and zero ductility temperature (ZDT) in the Mushy Zone were quantitatively determined, and the critical strain threshold associated to hot crack initiation in the brittle region were further evaluated following empirical model proposed by Y Won. Results show that the tensile strength and fracture ductility in the Mushy Zone are both closely associated with the varying volume fraction of network-shaped structure during solidification, and are decreased with decreasing solid fraction concerning studied 1.5 wt% Si and 6.5 wt% Si steels. The high temperature brittle region corresponding to the studied 1.5 wt% Si and 6.5 wt% Si steels in Mushy Zone are separately confirmed to be 1459 ~ 1465℃ and 1390 ~ 1427℃, and the thresholds of critical strain for hot cracks initiation in high temperature brittle region are calculated to be ~ 1.18% and ~ 0.24%, respectively. Considering from perspective of width of high temperature brittle region and critical strain threshold for hot crack initiation, the cracking sensitivity of 6.5 wt% Si steel in the Mushy Zone is more serious compared to 1.5 wt% Si steel.
Andre Phillion - One of the best experts on this subject based on the ideXlab platform.
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Evolution of a Mushy Zone in a static temperature gradient using a volume average approach
Acta Materialia, 2017Co-Authors: Andre Phillion, G. Reinhart, H. Nguyen Thi, G. Salloum-abou-jaoude, Miha Založnik, I. Spindler, N. Pinter, C.-a. Aledo, Guillaume Boussinot, Markus ApelAbstract:A volume average model to study the transition of a semi-solid Mushy Zone to a planar solid/liquid interface in a static temperature gradient is presented. This model simulates the principal phenomena governing Mushy Zone dynamics including solute diffusion in the interdendritic and bulk liquids, migration of both the solid-liquid interface and the Mushy-liquid boundary at the bottom and top of the Mushy Zone, and solidification. The motion of the solid-liquid interface is determined analytically by performing a microscopic solute balance between the solid and Mushy Zones. The motion of the Mushy-liquid boundary is more complex as it consists of a transition between the Mushy and bulk liquid Zones with rapidly changing macroscopic properties. In order to simulate this motion, a control volume characterized by continuity in the solute concentration and a jump in both the liquid fraction and the solute concentration gradient was developed. The volume average model has been validated by comparison against prior in-situ X-ray radiography measurements [1], and phase-field simulations [2] of the Mushy-to-planar transition in an Al-Cu alloy. A very good similarity was achieved between the observed experimental and phase-field dynamics with this new model even though the described system was only one-dimensional. However , an augmentation of the solute diffusion coefficient in the bulk liquid was required in order to mimic the convective solute transport occurring in the in situ X-ray study. This new model will be useful for simulating a wide range of natural and engineering processes.
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3-D multi-scale modeling of deformation within the weld Mushy Zone
Materials & Design, 2016Co-Authors: H.r. Zareie Rajani, Andre PhillionAbstract:Abstract The deformation of the fusion weld Mushy Zone, as a critical factor in solidification cracking, has been simulated by combining a 3D multi-scale model of solidification and microstructure with a deformation model that includes the effects of solidification shrinkage, thermo-mechanical forces and restraining forces. This new model is then used to investigate the role of welding parameters on the deformation rate of micro liquid channels during Gas Tungsten Arc welding of AA6061. It is shown that the internal normal deformation rate due to solidification shrinkage and also the external normal deformation rate caused by external forces are both highest for the micro liquid channels at the center of the Mushy Zone where solidification cracks usually occur. Furthermore, the model shows that welding travel speed and welding current strongly influence the deformation rate of the weld Mushy Zone and consequently the solidification cracking susceptibility of the weld. The model can be also used to link micro-scale phenomena with the macro-scale characteristics of solidification cracking during welding.
Markus Rettenmayr - One of the best experts on this subject based on the ideXlab platform.
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resolidification of the Mushy Zone of multiphase and multicomponent alloys in a temperature gradient experiments and modeling
Acta Materialia, 2015Co-Authors: Andrea Löffler, Klemens Reuther, Hannes Engelhardt, Dongmei Liu, Markus RettenmayrAbstract:Abstract Resolidification of the Mushy Zone of multiphase and multicomponent alloys in a temperature gradient is investigated. Experiments of gradient annealing are conducted for a multiphase Cu-40 wt.%Al alloy and an Al-1 wt.%Mg-5 wt.%Si alloy with varying holding times, and the resulting microstructures are evaluated with respect to the evolution of phase fractions and concentration distributions. A numerical model that describes the macroscopic mass transport along the temperature gradient out of the Mushy Zone and that predicts the evolution of phase fractions and concentration distributions for multicomponent and multiphase alloys is put forward, and the calculation results are compared with the experimental observations. Full qualitative agreement is achieved between experiment and simulation. Effects in a resolidifying Mushy Zone of a multiphase alloy such as local solutal melting prior to resolidification that have so far not been documented in the literature are captured by the model.
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Resolidification of the Mushy Zone of multiphase and multicomponent alloys in a temperature gradient – Experiments and modeling
Acta Materialia, 2015Co-Authors: Andrea Löffler, Klemens Reuther, Hannes Engelhardt, Dongmei Liu, Markus RettenmayrAbstract:Abstract Resolidification of the Mushy Zone of multiphase and multicomponent alloys in a temperature gradient is investigated. Experiments of gradient annealing are conducted for a multiphase Cu-40 wt.%Al alloy and an Al-1 wt.%Mg-5 wt.%Si alloy with varying holding times, and the resulting microstructures are evaluated with respect to the evolution of phase fractions and concentration distributions. A numerical model that describes the macroscopic mass transport along the temperature gradient out of the Mushy Zone and that predicts the evolution of phase fractions and concentration distributions for multicomponent and multiphase alloys is put forward, and the calculation results are compared with the experimental observations. Full qualitative agreement is achieved between experiment and simulation. Effects in a resolidifying Mushy Zone of a multiphase alloy such as local solutal melting prior to resolidification that have so far not been documented in the literature are captured by the model.
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Mushy Zone Resolidification in a Temperature Gradient in Multiphase and Multicomponent Alloys
Materials Science Forum, 2014Co-Authors: Andrea Löffler, Markus RettenmayrAbstract:A model for simulating Mushy Zone resolidification in a temperature gradient is presented. For describing macroscopic mass transport in the liquid phase in the Mushy Zone, an extended diffusion equation is solved numerically using the Finite Difference Method. Temperature dependent local equilibria at each position in the Mushy Zone are calculated using the thermodynamic software package ChemApp. The resolidification model treats multicomponent alloying systems and accounts for multiphase equilibria. Simulation results for peritectic Cu-40wt%Al and eutectic Al-5wt%Si-1wt%Mg alloys are compared with microstructures from temperature gradient annealing experiments. It is shown that the model is well suited to predict Mushy Zone resolidification in multicomponent and multiphase alloys. The predicted evolution of the liquid fraction is qualitatively in full agreement with the observed microstructures, including local remelting at the peritectic temperature prior to resolidification, an effect that was first predicted by the model and confirmed by the experiments.
Peng Peng - One of the best experts on this subject based on the ideXlab platform.
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macrosegregation and thermosolutal convection induced freckle formation in dendritic Mushy Zone of directionally solidified sn ni peritectic alloy
Journal of Materials Science & Technology, 2021Co-Authors: Peng Peng, Jinmian Yue, Anqiao Zhang, Xudong ZhangAbstract:Abstract Compared with the growing applications of peritectic alloy, none research on the freckle formation during peritectic solidification has been reported before. Observation on the dendritic Mushy Zone of Sn-36 at.%Ni peritectic alloy during directional solidification at different growth velocities shows that the freckles are formed in two different regions: region I before peritectic reaction and region II after peritectic reaction. In addition, more freckles can be observed at lower growth velocities. Examination on the experimental results demonstrates that both the temperature gradient Zone melting (TGZM) and Gibbs-Thomson (G–T) effects have obvious influences on the morphology of dendritic network during directional solidification. The current theories onKI Rayleigh number Ra characterizing the thermosolutal convection of dendritic Mushy Zone to predict freckle formation through the maximum of Ra can only explain the existence of region I while the appearance of region II after peritectic reaction cannot be predicted. Thus, a new Rayleigh number RaP is proposed in consideration of evolution of dendritic Mushy Zone by both effects and peritectic reaction. Theoretical prediction of RaP also shows a maximum after peritectic reaction in addition to that before peritectic reaction, thus, agreeing well with the freckle formation in region II. In addition, more severe thermosolutal convection can be predicted by the new Rayleigh number RaP at lower growth velocities, which further demonstrates the reliability of RaP in describing the dependence of freckle formation on growth velocity.
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migration of liquid particle from Mushy Zone interface in temperature gradient
International Journal of Heat and Mass Transfer, 2019Co-Authors: Peng PengAbstract:Abstract The thermal stabilization process after which directional growth of crystals initiates is crucial in obtaining the initial growth conditions of directional solidification. A Mushy Zone is formed during thermal stabilization due to the imposed temperature gradient. The difference in melt concentrations across the liquid particles in the Mushy Zone induces simultaneous remelting/resolidification by the temperature gradient Zone melting (TGZM), and this phenomenon is called the migration of liquid particle. It is usually assumed that the migration of liquid particle initiates from the superheated solid phases in the Mushy Zone in single phase alloy. However, the migration of liquid particles from the Mushy Zone interface at peritectic temperature TP during thermal stabilization has been confirmed in a Sn–Ni peritectic alloy (Liquid + Ni3Sn2 → Ni3Sn4) in this work. This newly observed migration of the liquid particles from the Mushy Zone interface has been described to simultaneous remelting/resolidification at the leading/trailing interface of the liquid particles through a diffusion-controlled analytical model.
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Analysis on fluid permeability of dendritic Mushy Zone during peritectic solidification in a temperature gradient
Journal of Materials Science & Technology, 1Co-Authors: Peng Peng, Jinmian Yue, Anqiao Zhang, Xudong ZhangAbstract:Abstract Compared with the growing applications of peritectic alloys, none research on the fluid permeability K of dendritic network during peritectic solidification has been reported before. The fluid permeability K of dendritic network in the Mushy Zone during directional solidification of Sn-Ni peritectic alloy was investigated in this study. Examination on the experimental results demonstrates that both the temperature gradient Zone melting (TGZM) and Gibbs-Thomson (G–T) effects have obvious influences on the morphology of dendritic network during directional solidification. This is realized through different stages of liquid diffusion within dendritic Mushy Zone by these effects during directional solidification. The TGZM effect is demonstrated to play a more important role as compared with the G–T effect during directional solidification. Besides, it is shown that the evolution of dendrite network is more complex during peritectic solidification due to the involvement of the peritectic phase. Through the specific surface SV, analytical expression based on the Carman–Kozeny model was proposed to analyze the fluid permeability of dendritic Mushy Zone in directionally solidified peritectic alloys. In addition, it is interesting to find a rise in permeability K after peritectic reaction in both theoretical predication and experimental results, which is different from that in other alloys. The theoretical predictions show that this rise in fluid permeability K after peritectic reaction is caused by the remelting/resolidification process on dendritic structure by the TGZM and G–T effects during peritectic solidification.
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Macrosegregation and channel segregation formation of faceted Mushy Zone in solidification of Sn-Ni hypereutectic alloy in a temperature gradient
Materials Chemistry and Physics, 1Co-Authors: Peng Peng, Wanchao Zheng, Jiatai WangAbstract:Abstract Numerous investigations on the macrosegregation and channel segregation formation have been reported during eutectic solidification. However, the current analyses are focused on the non-faceted dendritic Mushy Zone while the faceted Mushy Zone during solidification has not been reported before. In this work, the macrosegretion and channel segregation formation are studied in directional solidification of Sn-15at.%Ni hypereutectic alloy where the solidified Ni3Sn4 phase exhibits faceted lath-type growth morphology. Similar to previous works on non-faceted Mushy Zone, more channels can be witnessed in the (Liquid+Ni3Sn4) Mushy Zone at lower growth velocities. More obvious macrosegregation can be formed in samples at lower growth velocities where the thermosolutal convection is more severe. However, distinct from previous reports, the effective solute distribution coefficient is not constant in the faceted Mushy Zone of this alloy. Besides, the experimental results demonstrates that the convection can reduce the interspacing of Ni3Sn4 phase during directional solidification. In addition, the thermosolutal convection has more significant influence on the interspacing of Ni3Sn4 phase than the solutal buildup at the tip of Ni3Sn4 phase.
Xiaoming Zhang - One of the best experts on this subject based on the ideXlab platform.
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comparison of cracking sensitivity between high permeability 1 5 wt si steel and 6 5 wt si steel in Mushy Zone
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Yuanxiang Zhang, G. Yuan, Xiaoming Zhang, J.h. Zhao, Guodong WangAbstract:Abstract Twin-roll thin strip casting process (SC) has been utilized in laboratory to fabricate typical high-permeability electrical steel (HPES) such as 1.5 wt% Si and 6.5 wt% Si steel with ideal crystallographic orientation and excellent permeability after a series of heat treatments. Whereas, there exists a problem associated to the cracking sensitivity in high temperature Mushy Zone, which further restricts the industrial application of SC to produce HPES. Mechanical behavior of 1.5 wt% Si and 6.5 wt% Si steels in high temperature Mushy Zone were comparatively studied by Gleeble-3800 physical simulation system under strain rate 3 s−1, systematically. The high temperature brittle region composed of zero strength temperature (ZST) and zero ductility temperature (ZDT) in the Mushy Zone were quantitatively determined, and the critical strain threshold associated to hot crack initiation in the brittle region were further evaluated following empirical model proposed by Y Won. Results show that the tensile strength and fracture ductility in the Mushy Zone are both closely associated with the varying volume fraction of network-shaped structure during solidification, and are decreased with decreasing solid fraction concerning studied 1.5 wt% Si and 6.5 wt% Si steels. The high temperature brittle region corresponding to the studied 1.5 wt% Si and 6.5 wt% Si steels in Mushy Zone are separately confirmed to be 1459 ~ 1465℃ and 1390 ~ 1427℃, and the thresholds of critical strain for hot cracks initiation in high temperature brittle region are calculated to be ~ 1.18% and ~ 0.24%, respectively. Considering from perspective of width of high temperature brittle region and critical strain threshold for hot crack initiation, the cracking sensitivity of 6.5 wt% Si steel in the Mushy Zone is more serious compared to 1.5 wt% Si steel.
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Comparison of Cracking Sensitivity Between High-permeability 1.5 wt.% Si Steel and 6.5 wt.% Si Steel in Mushy Zone
Journal of Magnetism and Magnetic Materials, 2020Co-Authors: Hu Wei, Zhang Yuanxiang, G. Yuan, Xiaoming Zhang, J.h. Zhao, Guodong WangAbstract:Abstract Twin-roll thin strip casting process (SC) has been utilized in laboratory to fabricate typical high-permeability electrical steel (HPES) such as 1.5 wt% Si and 6.5 wt% Si steel with ideal crystallographic orientation and excellent permeability after a series of heat treatments. Whereas, there exists a problem associated to the cracking sensitivity in high temperature Mushy Zone, which further restricts the industrial application of SC to produce HPES. Mechanical behavior of 1.5 wt% Si and 6.5 wt% Si steels in high temperature Mushy Zone were comparatively studied by Gleeble-3800 physical simulation system under strain rate 3 s−1, systematically. The high temperature brittle region composed of zero strength temperature (ZST) and zero ductility temperature (ZDT) in the Mushy Zone were quantitatively determined, and the critical strain threshold associated to hot crack initiation in the brittle region were further evaluated following empirical model proposed by Y Won. Results show that the tensile strength and fracture ductility in the Mushy Zone are both closely associated with the varying volume fraction of network-shaped structure during solidification, and are decreased with decreasing solid fraction concerning studied 1.5 wt% Si and 6.5 wt% Si steels. The high temperature brittle region corresponding to the studied 1.5 wt% Si and 6.5 wt% Si steels in Mushy Zone are separately confirmed to be 1459 ~ 1465℃ and 1390 ~ 1427℃, and the thresholds of critical strain for hot cracks initiation in high temperature brittle region are calculated to be ~ 1.18% and ~ 0.24%, respectively. Considering from perspective of width of high temperature brittle region and critical strain threshold for hot crack initiation, the cracking sensitivity of 6.5 wt% Si steel in the Mushy Zone is more serious compared to 1.5 wt% Si steel.
