Crystallographically degenerate B2 precipitation in a plastically deformed fcc-based complex concentrated alloy

BCC-ordered B2 and fcc phases manifest three different orientation relationships (ORs) in the same microstructure; Kurdjumov-Sachs, Nishiyama-Wasserman and Pitsch. This unique microstructure was developed via conventional cold-rolling and subsequent annealing of an fee-based Al0.3CoCrFeNi com pi ex con centra ted alloy (CCA) .The degeneracy in crystallographic ORs was caused by {111 }{112)twins, on multiple {111}, from the prior cold-rolling step. Annealing produced B2 precipitates on all the major fee slip-systems by heterogeneously nucleating B2 at twin-matrix interfaces and twin-twin intersections. Such a precipitation-hardenable microstructure is expected to increase the strength of fcc- based CCAs by effectively blocking 1/2(110)and 1/6(112)mobile dislocations. [GRAPHICS] IMPACT STATEMENT Three different fcc-B2 orientation relationships (ORs) were observed for the first time in complex concentrated alloys. Such degenerate ORs in B2 precipitation can potentially block dislocation on multiple slip planes.