采用CALPHAD(CALculation of PHAse Diagrams)方法重新对Mg-Al-Gd三元系进行评估,获得一套自洽的热力学参数。用Mg_(x)(TM,Mg)_(6)(RE,Mg)_(8)热力学模型(TM=过渡金属,RE=稀土金属)描述长周期堆积有序相14H和18R。计算代表性的等温截面...采用CALPHAD(CALculation of PHAse Diagrams)方法重新对Mg-Al-Gd三元系进行评估,获得一套自洽的热力学参数。用Mg_(x)(TM,Mg)_(6)(RE,Mg)_(8)热力学模型(TM=过渡金属,RE=稀土金属)描述长周期堆积有序相14H和18R。计算代表性的等温截面、垂直截面、液相线投影图和相关的零变量反应,与实验数据进行比较,表明所得热力学参数的可靠性。绘制了整个三元体系的反应图,并对几种Mg-Al-Gd合金的Scheil凝固路径和相分数进行计算和分析,清楚地描述了凝固过程中各相的形成以及γ和LPSO相的相分数随Gd成分的变化,这些是影响Mg-Al-Gd合金的显微硬度、极限抗拉强度和屈服强度的重要因素。展开更多
In this study,insights into the effect of interfacial anisotropy on a complex hexagonal close-packed(hcp) dendritic growth during alloy solidification were gained by graphics processing unit(GPU)-accelerated three-dim...In this study,insights into the effect of interfacial anisotropy on a complex hexagonal close-packed(hcp) dendritic growth during alloy solidification were gained by graphics processing unit(GPU)-accelerated three-dimensional(3D) phase-field simulations,as demonstrated for a Mg-Gd alloy.An anisotropic phasefield model with finite interface dissipation was developed by incorporating the contribution of the anisotropy of interfacial energy into the total free energy functional.The modified spherical harmonic anisotropy function was then chosen for the hcp crystal.The GPU parallel computing algorithm was implemented in the present phase-field model,and a corresponding code was developed in the compute unified device architecture parallel computing platform.Benchmark tests indicated that the calculation efficiency of a single TESLA V100 GPU could be~80times that of open multi-processing(OpenMP) with eight central processing unit cores.By coupling the phase-field model with reliable thermodynamic and interfacial energy descriptions,the 3D phase-field simulation of α-Mg dendritic growth in the Mg-6Gd(in wt%) alloy during solidification was performed.Various two-dimensional dendrite morphologies were revealed by cutting the simulated 3D dendrite along different crystallographic planes.Typical sixfold equiaxed and butterflied microstructures observed in experiments were well reproduced.展开更多
基金Projects(51304135,50971089)supported by the National Natural Science Foundation of ChinaProject(A1420110045)supported by National Defense Basic Research Plan,China+1 种基金Project(11QH1401200)supported by the Shanghai Phospherus Program,ChinaProject(NCET-11-0329)supported by the New Century Excellent Talents in University of Ministry of Education of China
基金The financial supports from the National Key Laboratory of Science and Technology on High-strength Structural Materialsthe National Natural Science Foundation of China(No.51771235)。
文摘采用CALPHAD(CALculation of PHAse Diagrams)方法重新对Mg-Al-Gd三元系进行评估,获得一套自洽的热力学参数。用Mg_(x)(TM,Mg)_(6)(RE,Mg)_(8)热力学模型(TM=过渡金属,RE=稀土金属)描述长周期堆积有序相14H和18R。计算代表性的等温截面、垂直截面、液相线投影图和相关的零变量反应,与实验数据进行比较,表明所得热力学参数的可靠性。绘制了整个三元体系的反应图,并对几种Mg-Al-Gd合金的Scheil凝固路径和相分数进行计算和分析,清楚地描述了凝固过程中各相的形成以及γ和LPSO相的相分数随Gd成分的变化,这些是影响Mg-Al-Gd合金的显微硬度、极限抗拉强度和屈服强度的重要因素。
基金supported by the Natural Science Foundation of Hunan Province for Distinguished Young Scholars (No. 2021JJ10062)National Key Research and Development Program of China (No. 2016YFB0301101)+2 种基金Science and Technology Program of Guangxi province, China (No. AB21220028)the financial support from the Fundamental Research Funds for the Central Universities of Central South University (No. 2019zzts050)Postgraduate Scientific Research Innovation Project of Hunan Province (No. CX20190106)。
文摘In this study,insights into the effect of interfacial anisotropy on a complex hexagonal close-packed(hcp) dendritic growth during alloy solidification were gained by graphics processing unit(GPU)-accelerated three-dimensional(3D) phase-field simulations,as demonstrated for a Mg-Gd alloy.An anisotropic phasefield model with finite interface dissipation was developed by incorporating the contribution of the anisotropy of interfacial energy into the total free energy functional.The modified spherical harmonic anisotropy function was then chosen for the hcp crystal.The GPU parallel computing algorithm was implemented in the present phase-field model,and a corresponding code was developed in the compute unified device architecture parallel computing platform.Benchmark tests indicated that the calculation efficiency of a single TESLA V100 GPU could be~80times that of open multi-processing(OpenMP) with eight central processing unit cores.By coupling the phase-field model with reliable thermodynamic and interfacial energy descriptions,the 3D phase-field simulation of α-Mg dendritic growth in the Mg-6Gd(in wt%) alloy during solidification was performed.Various two-dimensional dendrite morphologies were revealed by cutting the simulated 3D dendrite along different crystallographic planes.Typical sixfold equiaxed and butterflied microstructures observed in experiments were well reproduced.
基金supported by the National Natural Science Foundation of China(No.52071093,51871069)the Fundamental Research Funds for the Central Universities,China(No.3072021CF1008)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization,China(No.RERU2020012)。
基金financial supports from the National Key Research and Development Program of China(Nos.2016YFB0301000,2016YFB0701204)the National Natural Science Foundation of China(No.51821001).
基金supported by the Natural Science Foundation of Shanxi Province, China (Nos. 20210302123135, 20210302123163, 201901D211096, 201901D111272)Youth Program of National Natural Science Foundation of China (No. 51901153)+1 种基金Science and Technology Major Project of Shanxi Province, China (Nos. 20191102008, 20191102007, 20191102004)Shanxi Province Scientific Facilities and Instruments Shared Service Platform of Magnesium-based Materials Electric Impulse Aided Forming, China (No. 201805D141005)。
