Effect of Cu addition on microstructure, wear, and corrosion resistance of AlCoCrFeNiSi0.5Cux (x = 0.01, 0.05, 0.1) high-entropy alloys

Abstract The influence of copper addition on the structure and selected properties of AlCoCrFeNiSi 0.5 Cu x high-entropy alloys is described. Slowly cooled ingots were prepared by induction melting, and the samples in the form of plates were obtained by pressure casting. The conducted structural studies confirmed the presence of BCC/B2 phase. Microsegregation in the ingots was associated with the formation of intermetallic Cr 3 Si and Fe 5 Si 3 phases. An increase in the cooling rate stopped segregation by reducing the mobility of Cr and Si. The hyperfine magnetic field distributions indicated the formation of the BCC Fe(Co,Ni,Si,Cr) solid solution for alloys in the form of plates. The lowest corrosion-current density (0.04 μA/cm 2 ) in 3.5%-NaCl solution was obtained for the plate with the lowest copper content. The dominated aluminum surface states for the post-corrosive plates highlighted the binding energies of Al 2 O 3 . A tendency of reduced coercivity with increased copper content was observed. The positive effect of copper addition on wear resistance was confirmed for the AlCoCrFeNiSi 0.5 Cu 0.1 alloy.