Mechanical and tribological properties of (FeCoNi)_88-x(AlTi)₁₂Mo_x high-entropy alloys

In this study, we designed and prepared (FeCoNi)(88-x)(AlTi)(12)Mo-x high-entropy alloys (HEAs) with good comprehensive properties by vacuum arc melting technology. The influence of Mo content on the microstructure, mechanical properties, and tribological properties of the HEAs were systematically studied. The results showed that all HEAs in this study are simple fcc solid solution structure, all HEAs are composed of gamma + gamma' phase, and they are in a coherent relationship. The tensile test results show that all the HEAs exhibit excellent strength-ductility combination, and the final tensile fracture mechanism is a ductile fracture. Mo1.0 HEA has the best comprehensive mechanical properties, with the yield strength, tensile strength, and elongation of 980 MPa, 1260 MPa, and 34.5%, respectively. The reciprocating friction and wear test results show that the HEAs have excellent friction and wear properties. Compared with the four HEAs, the order of friction and wear properties from good to poor is Mo1.0 HEA, Mo1.5 HEA, Mo0.5 HEA, and Al6Ti6 HEA. The wear mechanisms of all HEAs are abrasive wear and oxidation wear, as well as the Al6Ti6 and Mo1.0 HEAs also have delamination wear.