Design of non-equiatomic high entropy alloys with heterogeneous lamella structure towards strength-ductility synergy

Heterogeneous lamella structured high entropy alloy is fabricated through thermal mechanical processing routes to overcome strength-ductility trade-off. Its unique grain structure containing both fine grained (FG) and coarse grained (CG) lamella is illustrated in the EBSD orientation map in the through thickness direction, along with the grain area map showing coarse grained lamella. Exceptional mechanical property is attributed to the back-stress strengthening, which is correlated to the generation of excess geometrically necessary dislocations near the CG-(soft)/FG-(hard) interface to maintain compatibility.317