Hot deformation behaviour and processing map of Co-Cu-Fe-Ni-Ti eutectic high entropy alloy

Multicomponent Co20Cu20Fe20Ni20Ti20 eutectic high entropy alloy (HEA), processed by vacuum arc melting cum suction casting technique was studied. The microstructure of this eutectic HEA consists bcc (β) and fcc (α2) solid solution dendritic phases and eutectics (fcc (α1) plus Ti2(Ni, Co)-type Laves phase). Serrations in the flow behaviour are attributed to multi substitutional solutes in the multi-phase microstructure. Based on the detailed analysis of mechanical data together with deformed microstructural characterization, the optimum thermo-mechanical processing conditions for hot working are identified as T=930-990 °C (1203-1263 K) and strain rate range of 10−3 s−1-10−1 s−1.