Fine-structured CoCrFeNiMn high-entropy alloy matrix composite with 12 wt% TiN particle reinforcements via selective laser melting assisted additive manufacturing

Abstract Selective Laser Melting (SLM) was employed for Additive Manufacturing (AM) of nearly equiatomic CoCrFeNiMn high-entropy alloy (HEA) and its matrix composite parts reinforced by 12 wt% nano-sized TiN particles (TiNP). HEA matrix microstructure of printed TiNP/HEA was remarkably refined and isotropic, rather than anisotropic coarse-grains of printed HEA in absence of TiNP. The ceramic reinforcements achieved a relatively uniform distribution in HEA matrix to contribute to the pinning effects for strengthening. High specific strength and good sliding-wear resistance of printed TiNP/HEA were achieved. The as-printed Gyroid architecture of TiNP/HEA exerted an elevated compression-resistance. The introduced TiNP, as a large number of nanoscale nucleation sites during SLM, benefits the formation of nearly equiaxed and ultrafine grains of HEA matrix for strengthening.