Microstructure and mechanical properties of Fe50Mn30Co10Cr10 high-entropy alloy with Si addition prepared by laser melting deposition

In this study, (Fe50Mn30Co10Cr10)100- xSix (x = 0, 4, 8, 12 at%) high-entropy alloys were successfully prepared by laser melting deposition technology. The effects of Si content on the microstructural evolution and mechanical properties of Fe50Mn30Co10Cr10 alloy were investigated. The results show that all the laser-deposited (Fe50Mn30Co10Cr10) 100-xSix alloys are FCC+ HCP dual-phase structure, and the volume fraction of HCP phase increases from 1.5 % to 39.3 % with the increase of Si content. Moreover, the hardness and ultimate tensile strength of the alloy increase with the increase of Si content, and the maximum values are 309.8 HV0.2 and 866 MPa, respectively. The elongation increases first and then decreases in the range of 25.8-34.3 %. The changes of mechanical properties of Si-containing Fe50Mn30Co10Cr10 HEAs are discussed based on the combined effects of solid solution strengthening, grain refinement, phase transition-induced plasticity and twinning induced plasticity effects.