Straining流对柱状晶体在三元过冷熔体中生长的影响  

Effect of straining flow on growth of columnar crystal in ternary undercooled melt

作　　者：范海龙 陈明文[1] Fan Hai-Long;Chen Ming-Wen(School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学数理学院,北京100083

出　　处：《物理学报》2020年第11期205-214,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11401021)资助的课题.

摘　　要：研究了三元过冷熔体中柱状晶体在非等温条件下受straining流作用的生长问题,给出了柱状晶体生长形态的近似解析表达式.发现流入的straining流加快了界面的生长速度,而流出的straining流减缓了界面的生长速度,即straining流使得柱状晶体的界面发生变形.同时发现,随着流动速度的增大,界面变形也更为显著.通过比较straining流对纯熔体、二元熔体、三元熔体中柱状晶体界面的影响,发现相比于纯熔体,柱状晶体在稀合金熔体中的界面形态受straining流的影响更大.As an important microstructure,columnar crystal growth technology,especially the growth technology of single columnar crystal plays an important role in improving the performances of semiconductor,optical devices and other related products.In many practical applications,because the alloy is composed of multi-component and there is inevitably flow in the melt,it is necessary to study the growth of columnar crystals in multicomponent melt with flow separately.The growth of columnar crystal in a ternary undercooled melt subjected to straining flow under non-isothermal conditions is studied,and the approximate analytical expression for growth morphology of columnar crystal is given by using asymptotic method.It can be seen from the expression that straining flow is an important reason for irregular columnar crystal.When analyzing the effect of straining flow on the growth of columnar crystal in ternary melt,it is found that the incoming flow accelerates the growth velocity of the interface,while the outgoing straining flow reduces the growth velocity of the interface,namely,the straining flow makes the interface of columnar crystal deformed.At the same time,it is found that the interface deformation becomes more intense with the increase of flow velocity.The above conclusion can also be applied to the effect of straining flow on the interface morphology of columnar crystal in pure melt and binary melt.The comparison of the effects of straining flow on the interface of columnar crystal among pure melt,binary melt and ternary melt,shows that the interface morphology of columnar crystal in dilute alloy melt is more affected by straining flow than in the pure melt,but the more components are more easily affected by flow.However,the number of components in melt is not a decisive factor for the change of interface morphology of the columnar crystal,but the constitutional undercooling is an important factor for determining the interface morphology of multicomponent alloy.According to the conclusion of this paper,the influen

关 键 词：柱状晶体 三元熔体 straining流 界面形态 

分 类 号：O782[理学—晶体学]