Artificial age hardening behavior of a squeeze cast CoCrFeMnNi high entropy alloy reinforced 6082-aluminium matrix composite

An Mg-Si-based 6082 aluminium metal matrix composite reinforced with varying concentrations of CoCrFeMnNi high-entropy alloy particles (HEAp) was processed through stir-squeeze casting. The composites were heat treated to examine the age-hardening effect on microstructural changes, fracture mechanism, and an interface between HEAp and aluminium matrix. The evolution of microstructure and topography of fractured surface was investigated through field emission scanning electron microscope with energy dispersive X-ray spectroscopy and transmission electron microscope to characterize the precipitate and intermetallic compound formed at Al/HEAp interface. X-ray diffraction is used to characterize phase evolution. The tensile test was performed to investigate the correlation between tensile strength and artificial ageing. Under the T6 condition, composites exhibit superior mechanical properties such as improved hardness, yield strength (Ys), and ultimate tensile strength (UTS), maximum values were reported as 94.01 HRB, 303 MPa, and 486 MPa respectively for 8 wt% HEA/AA (T6) however, the ductility of composites is less as compared to the as-cast condition which is due to the formation of precipitates.