A novel L1₂-strengthened AlCoCuFeNi high-entropy alloy with both high hardness and good corrosion resistance

Abstract

In this work, a high hardness, crack-free AlCoCuFeNi high-entropy alloy with good corrosion resistance was successfully produced by spark plasma sintering at 1000℃ and 30 MPa for 10 min, followed by hot rolling to a thickness reduction of 10 % after holding at 600℃ for 30 min. The microstructure of the alloy was composed of fine equiaxed grains of (Fe, Co, Ni, Al)-enriched BCC, Cu-enriched FCC, nano-sized L12, and Al2O3 phases. The maximum texture index of the material is only 1.53, indicating a low anisotropy. The alloy possessed a high hardness (599 HV), a low friction coefficient (0.1), and a low corrosion current density (1.13 μA/cm2), implying both good wear and corrosion resistance. In addition, the creep mechanism was found to be grain boundary sliding.