The effect of the shear flow on directional solidification of SCN-3wt% Salol alloy  

作　　者：WANG JianYuan CHEN ChangLe WANG KangNing JIN KeXin 

机构地区：[1]Shaanxi Key Laboratory of Condensed Matter Structures and Properties,Northwestern Polytechnical Uiversity,Xi’an 710072,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第5期742-746,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant Nos.50331040 and 50702046)

摘　　要：The directional solidification process of SCN-3wt%Salol transparent alloy is investigated in the presence of the shear flow at the liquid-solid interface.It is found that the shear flow induces a stabilizing effect on planar interface.At higher pulling rates,oscillation of the growth pattern together with fluctuation of the growth velocity takes place.With the increase of the pulling rate,the interface growth pattern transits from"planar-cellular"oscillation to"cellular-dendritic"oscillation,and the periodicity increases.The modification of the growth pattern is due to the effect of the shear flow on solute distribution,and the time and history dependent character of interface morphology evolution also plays an important role in the formation of the oscillating growth pattern.The directional solidification process of SCN-3wt% Salol transparent alloy is investigated in the presence of the shear flow at the liquid-solid interface. It is found that the shear flow induces a stabilizing effect on planar interface. At higher pulling rates, oscillation of the growth pattern together with fluctuation of the growth velocity takes place. With the increase of the pulling rate, the interface growth pattern transits from “planar-cellular” oscillation to “cellular-dendritic” oscillation, and the periodicity increases. The modification of the growth pattern is due to the effect of the shear flow on solute distribution, and the time and history dependent character of interface morphology evolution also plays an important role in the formation of the oscillating growth pattern.

关 键 词：shear flow OSCILLATING growth pattern directional SOLIDIFICATION MORPHOLOGICAL instability 

分 类 号：TG131[一般工业技术—材料科学与工程]