Microstructure, electrical conductivity and mechanical properties of CoCrFeNi-Cu composite

For investigating the effect of the admixture method of CoCrFeNi high-entropy alloys (HEAs) in Cu matrix composites on its microstructure and properties, the mechanically mixed CoCrFeNi-Cu powder, and gas atomization CoCrFeNi-Cu powder are prepared by spark plasma sintering technique, respectively. Several intermediates with core-shell structure exist in the specimen which is prepared using CoCrFeNi-Cu powder owing to the inter-elemental diffusion. It is assumed that the core-shell structure is effective in hindering grain deformation during cold rolling process and thus improves mechanical properties of the composites. The electrical conductivity, microhardness, and predicted ultimate tensile strength of the specimen prepared by mechanical mixing of Cu and CoCrFeNi powders were 69.09% IACS, 139.93 HV and 525.9 MPa, respectively.