The effect of heterogeneous microstructure of additively manufactured Ni2CoCrNb0.16 high-entropy alloy on its machinability and tool wear

Compared with traditional forming methods, the heterogeneous microstructure and the high-density dislocations, elemental segregation and inclusion particles in additive manufactured (AMed) parts have important effects on their surface integrity and tool wear. In this study, the microstructure of the Ni2CoCrNb0.16 high-entropy alloy (HEA) manufactured by directed energy deposition (DED) under as-built and different heat treatment conditions were examined using different material characterization techniques. From this, the effects of microstructure evolution on microhardness, cutting force, surface roughness, subsurface damage and tool wear were analyzed. The result indicates that there are significant differences in surface integrity and tool wear between the AMed samples under different heat treatment conditions. This study provided guidance for future applications of DED HEA in the industry.