Improvement in mechanical as well as magnetic properties of a (FeCoNi)90Ti10-xAlx complex concentrated alloy series by tuning the chemical order

Abstract

There is considerable interest in magnetic materials which also possess good mechanical properties. Hence, the effect of Ti/Al ratio on the microstructure, mechanical and magnetic properties of (FeCoNi)₉₀Ti_10-xAl_x complex concentrated alloys (CCA) was investigated. An increase in the Ti/Al ratio in these CCA enhanced chemical ordering and substantially improved selected mechanical and magnetic properties. As the Ti/Al ratio changed from 10 to 0, the ductility increased from 7.5 to close to 50 %, the saturation magnetization (M_s) increased from 115.2 to 136.7 emu/g, and the coercivity (H_c) decreased from 17.9 to 4.2 Oe. The Fe₃₀Co₃₀Ni₃₀Ti₅Al₅ alloy exhibit higher UTS×EL value than available soft magnetic materials and has relatively higher M_s and lower H_c compared with other CCA. These results provide a methodology to modulate the chemical order in the Fe-Co-Ni system by Al and Ti additions and synergistically tune the mechanical and magnetic properties for high performance rotating electrical machine applications.