Effects of Cr content and electromagnetic stirring on the phase separation of Cu-Cr alloy

Abstract

The Cu-Cr immiscible alloys were prepared by arc melting. The effects of Cr addition and electromagnetic stirring on the phase separation, microstructure were examined. The results show that serious phase segregation occurs at the center of the sample with increasing Cr contents, forming a sandwich like structure. The shape of the primary Cr transforms from fine dendrite to more developed dendrite. Thermodynamic analysis indicates that Cr addition increases the driving force for the liquid phase separation. The electromagnetic stirring can facilitate elative motion between the Cr droplets and the melts, and thus intensify the segregation phenomenon. With Cr additions, the hardness in non-segregated area shows only slight increase, and in Cr segregated area shows a significant increase. While the electrical conductivity shows only slight decrease with increasing Cr content.