Phase Selection and Mechanical Properties of CoCrFexNiMn Multicomponent Alloys With Equivalent Electron Concentrations

A group of CoCrFe x NiMn ( x = 0.2, 4, 8 and 16, hereafter abbreviated as Fe x ) multicomponent alloys with equal valence electron concentrations (VECs = 8.00) are prepared. The effect of Fe addition on the microstructure and mechanical properties are investigated. The results reveal that the crystal structures of Fe x alloys change from a single FCC solid solution (Fe0.2 and Fe4 alloys) to an FCC + BCC dual-phase (Fe8 alloy) and then to a single BCC solid solution (Fe16 alloy) as the Fe content increases. A good combination of strength and plasticity is obtained in the Fe8 alloy, which benefits from the deformation-induced martensitic transformation (FCC-to-BCC) and the consequent transformation-induced plasticity (TRIP) and twin-induced plasticity (TWIP) effects. The phase selection rule and deformation mechanism behind the alloys are significant references for alloy design and mechanical property optimization.