Research on Microstructure and Mechanical Properties of Non-equiatomic AlCoCrFeNi High-entropy Alloys

Author of the article:LI Hongchao, WANG Jun, ZHAO Mengmeng, WANG Yi, LI Jinshan

Author's Workplace：State Key Laboratory of Solidification Processing, Northwestern Polytechnical University

Key Words： high-entropy alloy; non-equal atomic ratio; mechanical properties; microstructure

Abstract：The microstructure and mechanical properties of as-cast non-equal atomic ratio Al 0.5 (Co, Cr, Fe, Ni) 4 high
entropy alloy were studied by changing the contents of Co, Cr, Fe and Ni. The results show that the increase of Cr
increases the volume fraction of BCC phase, while the increase of Fe, Co and Ni increases the volume fraction of FCC
phase. For Al 0.5 (Co, Cr, Fe, Ni) 4 alloy with high content of Co-Fe, Co-Ni and Fe-Ni, spherical secondary phase is
precipitated in BCC phase, while for Cr-Ni and Co-Cr alloy, amplitude-modulated decomposition structure and cube-shaped
precipitated phase are generated in BCC phase. Whats more, the layered structure of block fcc interconnections, with bcc
phases distributed between these phases, was formed in the as-cast Al 0.5 Co 0.8 Cr 1.2 Fe 1.2 Ni 0.8 alloy, this unique structure make its
tensile strength and elongation reached 1 049 MPa and 11.2%, respectively.