摘要
采用数值模拟研究基于低过热度剪切制浆机铝合金凝固初期非枝晶组织的形成。采用格子玻尔兹曼法和相场法相结合,模拟枝晶在凝固过程中的生长和运动。模拟结果表明,充分的剪切流有助于浓度场的均匀化、晶体的旋转和非枝晶的形成。讨论晶粒间的相互作用。在枝晶臂部分重熔的基础上,建立LSPSF枝晶断裂判据,发现强剪切流和较大的倾斜角度能够增强枝晶断裂,并对模拟结果进行实验验证。
The formation of non-dendritic structures in the primary phase of an aluminum alloy solidified using low superheat pouring with a shearing field(LSPSF) machine was investigated by numerical simulation.The growth and motion of a dendrite during solidification was simulated by a combination of the lattice Boltzmann method and the phase field method.The simulation results indicated that enough shear flow helped homogenize the concentration fields,rotate crystals and altere microstructures from dendritic to non-dendritic.The interaction of grains was also discussed.A fragmentation criterion was established based on partial remelting of dendrite arms;fragmentation was enhanced by a strong shear flow and larger inclined angles.The simulation results were verified experimentally.
作者
吁安山
杨湘杰
郭洪民
An-shan YU;Xiang-jie YANG;Hong-min GUO(School of Mechanical and Electrical Engineering,Nanchang University,Nanchang 330031,China;Key Laboratory of Near Net Forming in Jiangxi Province,Nanchang 330031,China;School of Materials Science and Engineering,Nanchang University,Nanchang 330031,China)
基金
Project(51674144)supported by the National Natural Science Foundation of China
Project(KJLD14016)supported by the Luodi Research Plan of Jiangxi Educational Department,China
Projects(20122BAB206021,20133ACB21003)supported by the Natural Science Foundation of Jiangxi Province,China
Project(20122BCB23001)supported by the Young Scientists Cultivating Program of Jiangxi Province,China
关键词
数值模拟
非枝晶组织
低过热度剪切制浆(LSPSF)
铝合金
相场法
格子玻尔兹曼法
numerical simulation
non-dendritic structure
low superheat pouring with shearing field(LSPSF)
aluminum alloy
phase field method
lattice Boltzmann method
