Mechanism of reduction of columnar dendrite spacing in unidirectional solidification caused by electric current passing through solid-liquid interface

来源期刊：中国有色金属学报(英文版)2000年第5期

论文作者：常国威 袁军平 王自东 吴春京 王新华 胡汉起

文章页码：610 - 613

Key words：Cu-Al alloy; unidirectional solidification; columnar dendrite spacing; mechanism of current effect

Abstract: Considering the S-L interface morphology stability, the S-L interface energy, the Joule heat produced by electric current at the S-L interface, and the change of solute concentration at the S-L interface indirectly caused by electric current, the mechanism of reduction of columnar dendrite spacing in unidirectional solidification caused by electric current passing through solid-liquid interface was studied. The following conclusions can be drawn that: 1) under sub-rapid solidification condition, increasing electric current density will improve the stability of S-L interface, thus decreasing the columnar dendrite spacing; 2)there are two ways by which the increase of electric current decreases the columnar dendrite spacing, one is promoting the splitting of the protruding tips at the S-L interface, the other is promoting the forming of new convex parts at the bottom of the concave interface.