Effects of Al and Ti on microstructure, mechanical properties and wear resistance of TiXCrFe2Ni2 alloys

Individual effects of Al and Ti on microstructure, mechanical and tribological properties of CrFe2Ni2 alloy were investigated. Al addition changed the alloy from a FCC phase to a mixture of FCC, A2 and B2 phases, increasing the mechanical strength at slight expense of ductility. While Ti made the alloy composed of the FCC phase with L12-Ni3Ti nanoparticles, DO24 η-Ni3Ti and C14 Fe2Ti phases. Higher Ti contents caused a brittle Chi phase. The hard phases considerably hardened the Ti-containing alloys but markedly decreased the ductility of the alloys. Al appeared to be unfavorable for the wear resistance possibly due to inadequate balance between strength and weakened ductility, while Ti enhanced the wear resistance thanks to the hard phases. The detailed characterization would help guide tuning relevant HEAs for optimal tribological applications.