ABSTRACT

A novel 3d transition metal high entropy alloy (3d TM HEA), Al_0.5CoCuNiTi, was prepared by arc-melting. The phase component, microstructure, and mechanical properties in as-cast and annealed conditions were investigated. The results showed the phase structures of the studied alloys in both states were composed of FCC and BCC. The BCC phase was the absolute primary phase with a volume fraction of 84%. The FCC phase corresponded to Cu-rich regions, forming a continuous interdendritic regions wrapping the BCC dendrites. Compared to the majority of the reported single-phase FCC 3d TM HEAs, the alloys under both conditions possessed a promising trade-off in strength and plasticity. Specifically, the yield strength (σ_0.2) was 1130 and 996 MPa for the as-cast and annealed states, respectively. The compressive strain was more than 15% in both states. In the present work, the combination of phase constitution, morphology, and solid-solution strengthening was performed to justify the mechanical behaviour.

摘要

通过电弧熔化制备了一种新型的3d过渡金属高熵合金（3d TM HEA）Al _0.5 CoCuNiTi。研究了铸态和退火条件下的相成分，显微组织和力学性能。结果表明，两种状态下所研究合金的相结构均由FCC和BCC组成。BCC相是绝对主相，体积分数为84％。FCC相对应于富铜区域，形成包裹BCC树突的连续树突间区域。与大多数报道的单相FCC 3d TM HEA相比，两种条件下的合金在强度和可塑性方面都具有可观的折衷。具体而言，屈服强度（σ _0.2铸态和退火态的）分别为1130 MPa和996 MPa。在这两种状态下，压缩应变均超过15％。在目前的工作中，相结构，形态和固溶强化相结合以证明机械性能是正确的。