Rapid solidification of Cu60Co30Cr10 alloy under different conditions
(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)
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