轴向磁场下多晶硅定向凝固研究  

Study on Directional Solidification of Polycrystalline Silicon under Axial Magnetic Field

作　　者：刘志辉[1] 罗玉峰[1,2] 饶森林 胡云[3,4] 张发云 龚洪勇[3,4] 刘杰 

机构地区：[1]南昌大学机电工程学院,江西南昌330031 [2]华东交通大学,江西南昌330013 [3]新余学院,江西新余338004 [4]江西省高等学校硅材料重点实验室,江西新余338004

出　　处：《热加工工艺》2018年第1期88-91,95,共5页Hot Working Technology

基　　金：国家自然科学基金项目(51164033,51664047,51561022,61306084);江西省自然科学基金项目(20132BAB206021);江西省高等学校科技落地计划项目(KJLD12050);江西省教育厅科学技术研究项目(GJJ151220,11739,12748)

摘　　要：利用有限元软件COMSOL Multiphysics对多晶硅定向凝固过程进行二维数值模拟,研究轴向磁场对多晶硅定向凝固的影响。模拟结果显示,未加磁场时多晶硅固液界面的等温线是下凹的;当线圈中加以不同的电流进行磁场模拟时,发现轴向磁场能够有效地抑制硅熔体对流,进而影响结晶时的固液界面。随着电流的增大,熔体最大流速减小,最大洛伦兹力也增大。通过试验验证,相同的工艺条件,在磁场作用下相比于没有磁场时硅锭的界面由下凹变得平滑。The two-dimensional numerical simulation of directional solidification process of polycrystalline silicon was carried out by using finite element soflware COMSOL Multiphysics, and the influence of axial magnetic field on the directional solidification of the polycrystalline silicon was studied. The simulation results show that the isotherm of the solid-liquid interface of the polycrystalline silicon is concave without magnetic field. When the coils are subjected to different currents to simulate the magnetic field, it is found that the axial magnetic field can effectively restrain the convection of silicon melt, and then affect the solid-liquid interface. With the increase of current; the maximum flow velocity decreases and the maximum Lorenz force increases. It is verified by the experiments that compared with that without magnetic field, the ingot interface changes from concave to smooth under magnetic field.

关 键 词：多晶硅 定向凝固 数值模拟 轴向磁场 熔体对流 

分 类 号：TG244[金属学及工艺—铸造]