中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 10 No. 5 October 2000 |
unidirectional solidification caused by electric current passing
through solid-liquid interface①
（1. School of Metallurgy, University of Science and Technology Beijing, Beijing 100083, P.R.China;
2. Liaoning Institute of Technology, Jinzhou 121001, P.R.China;
3. Guangzhou Nonferrous Metal Institute, Guangzhou 510651, P.R.China;
4. School of Materials Science and Engineering, University of Science and Technology Beijing,
Beijing 100083, P.R.China）
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.
Key words: Cu-Al alloy; unidirectional solidification; columnar dendrite spacing; mechanism of current effect
