Solidification Microstructures in 3d-transition Metal High Entropy Alloys with Cu Element

I n this study, high-entropy alloys ( H E A s ) with C u a s the main constituent element were investigated, focusing o n the distribution o f C u i n the ingots. Based o n the taxonomy o f H E A s, those with C u a s the casting material were classified a s (1) H E A s whose main constituent elements were 3 d transition metals, such a s C o, C r, F e, M n, N i, and C u (3 dH E A s ), and (2) high-entropy ( H E ) brasses based o n the C u-Z n alloy system and H E bronzes based o n C u-S n and/or Cu-Al alloy systems. I n the case o f 3 d-H E A s with C u, the distribution o f C u i n the ingots exhibited the following tendency: (1 -1 ) segregation from the dendrite t o the residual liquid, resulting i n the formation o f Cu-rich inter d e n d r i t i c regions i n the ingots; (1-2) liquid-phase separation resulting i n the formation o f a Cu-rich liquid, which formed a macroscopically phase-separated structure; and (1-3) the dispersion o f fine C u precipitates embedded i n the solid solution matrix.