REN Zhongming Shanghai University

Spoluautoři LI Xi, LI Chuangjun, ZHONG Yunbo, YU Jianbo, XUAN Weidong, REN Xingfu

Over last decade the research work on solidification of alloys in a static magnetic field has gained much progress. The magnetic field has shown significant influence on solidification of alloys in nucleation, solid/liquid interface stability during growth, dendrite morphology, eutectic structure, columnar to equaxed transition, segregation, etc. Some new effects of magnetic field on solidification have been discovered. It was found that the nucleation undercoolings of several nonmagnetic alloys changed in strong magnetic field, which may be attributed to the new found phenomena that magnetic field influences the surface and interfacial tension of the materials. Thermoelectric magnetic(TEM) force is found playing a significant role in modification of growth behavior of alloys. The convection produced by TEM force in the interdendritic liquid was observed with synchrotron. The convections in the liquid in the scale of crucible and dendrite lead to change in dendrites morphology and composition distribution. Stress in the solid due to the TEM force was investigated, which may causes instability of the S/L interface and broken of the dendrites. Several experimental works have revealed that static magnetic field will also influence diffusion of atoms in alloys. Magnetic force due to magnetic field gradient and difference in magnetic susceptibility will drive grains to migrate, induce convection in liquid, deform shape of liquid surface, which will influence solidification structure.

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