2020 年 59 巻 1 号 p. 24-31
The ingots of CuxZnMnNi (x=1, 2) medium–entropy (ME) brasses were fabricated by metallic mold casting process without using a vacuum chamber. The molten metal was obtained by the high–frequently melting of the mixture of pure Cu, pure Ni, pre–alloy ingots of Mn–Cu and Zn–Ni using silica–based crucible under Ar flow, then the metallic mold casting ingots were obtained by the centrifugal casting under air atmosphere. The composite of body–centered–cubic (BCC) and face–centered–cubic (FCC) phases were obtained in the ingots of equiatomic CuZnMnNi ME brass, while a single FCC phase was obtained in the ingots of non–equiatomic Cu2ZnMnNi ME brass, where the identification of the constituent phases was mainly performed by XRD analysis. The ingots showed superior deformability and high 0.2% proof stress during compression test at room temperature.