Microstructure and Properties of Non-Equiatomic Ni₁₀Cr₆WFe₉TiAlx High-Entropy Alloys Combined with High Strength and Toughness

High-entropy alloys (HEAs) with excellent mechanical properties have broad application scope and application prospects. However, it is difficult to obtain the optimized element composition, based on the traditional equiatomic or near-equiatomic statistical analysis of the phase selection rules. The non-equiatomic HEAs have abundant constituents combination by optimizing the type and content of elements. In this study, Ni₁₀Cr₆WFe₉TiAlx (x = 0, 1.0 and 1.5, at.%) HEAs were prepared by vacuum arc melting. The effect of Al content x on microstructure and mechanical properties of HEAs was systematically studied. The results show that the HEAs are composed mainly of face-centered cubic (FCC) with hexagonal Al₂W phase. The increase of Al content promotes the formation of the hexagonal Al₂W phase. When the Al mole content is 1.0, the Ni₁₀Cr₆WFe₉TiAl HEA material has achieved superior mechanical properties. The alloy exhibited a high ultimate tensile strength of 741 MPa and a large total elongation of 46%. The improvement in the mechanical properties of the Ni₁₀Cr₆WFe₉TiAl HEA is mainly attributed to the precipitation strengthening of the high-density Al₂W phase. This work provides a reference for the future design of Al₂W precipitation-strengthened non-equiatomic HEAs with ideal properties.