Effect of Cu content on the microstructure, mechanical and corrosion behavior of AlFeNiMnCux high-entropy alloys

Abstract

The microstructure, mechanical and corrosion behavior of AlFeNiMnCu_x (x = 0.5, 0.75, 1.0, 1.25) high-entropy alloys (HEAs) have been investigated. It is identified as the BCC solid solution. An increase in concentration of Cu promotes the formation of reinforced phases and increases solid solution strengthening, which enhances mechanical properties. Additionally, the incorporation of Cu results in the formation of FCC structures, which in turn facilitates the transformation of corrosion modes and thus inhibits the corrosion. Among the studied HEAs, AlFeNiMnCu HEA (x = 1.0) is particularly noteworthy on mechanical properties, exhibiting a yield strength of 1559 MPa, a fracture strength of 1699 MPa, a plastic strain of 14.3%, and a Vickers hardness of 563 HV. And AlFeNiMnCu HEA also exhibits excellent performance in electrochemical corrosion, as indicated by an E_corr of -678.5 mV and an I_corr of 22.7 μA/cm². The results demonstrate that an increase in the Cu content has significant implications for microstructure, mechanical and corrosion behavior.