Mechanical alloying and spark plasma sintering of CoCrFeNiMnAl high-entropy alloy

An equiatomic CoCrFeNiMnAl high-entropy alloy was synthesized by mechanical alloying, and alloying behaviors, microstructure and annealing behaviors were investigated. It was found that a solid solution with refined microstructure of 20 nm in grain size could be obtained after 30 h milling. As-milled powder transformed into a face-centered cubic phase above 500 °C. The as-milled powder was subsequently consolidated by spark plasma sintering at 800 °C, BCC phase and FCC phase coexisted in the consolidated HEA, which had excellent properties in Vickers hardness of 662 HV and compressive strength of 2142 MPa.