中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 23 No. 3 March 2013 |
(1. Key Laboratory of Space Applied Physics and Chemistry of Ministry of Education,
Department of Applied Physics, Northwestern Polytechnical University, Xi’an 710072, China;
2. Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, Ministry of Education,Xi’an Jiaotong University, Xi’an 710049, China)
Abstract:Metastable liquid phase separation and rapid solidification in a metastable miscibility gap were investigated on the Cu60Co30Cr10 alloy by using the electromagnetic levitation and splat-quenching. It is found that the alloy generally has a microstructure consisting of a (Co,Cr)-rich phase embedded in a Cu-rich matrix, and the morphology and size of the (Co,Cr)-rich phase vary drastically with cooling rate. During the electromagnetic levitation solidification processing the cooling rate is lower, resulting in an obvious coalescence tendency of the (Co,Cr)-rich spheroids. The (Co,Cr)-rich phase shows dendrites and coarse spheroids at lower cooling rates. In the splat quenched samples the (Co,Cr)-rich phase spheres were refined signi?cantly and no dendrites were observed. This is probably due to the higher cooling rate, undercooling and interface tension.
Key words: Cu-Co-Cr alloy; rapid solidification; metastable liquid phase separation; electromagnetic levitation; splat-quenching