Development and homogeneity of microstructure and texture in a lamellar AlCoCrFeNi2.1 eutectic high-entropy alloy severely strained in the warm-deformation regime

The effect of severe warm rolling on microstructure and texture homogeneities was investigated in a lamellar (L1(2) + B2) AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA). The EHEA 90% warm-rolled at 400 degrees C showed disordering of the L1(2) phase and a remarkable increase in hardness. A much finer microstructure was observed on ND-RD (Normal Direction-Rolling Direction) plane as compared with that on the RD-TD (Rolling Direction-Transverse Direction) plane. The L1(2)/Face Centered Cubic (FCC) phase developed alpha-fiber texture ND//< 110 > with a particularly strong brass ({110}< 112 >) component, while the B2 phase developed the usual RD (//< 110 >) and ND (//< 111 >) fibers. Nevertheless, inhomogeneities in texture were noticed. Upon annealing at 800 degrees C, the ND-RD showed an ultrafine microduplex structure, while the RD-TD showed a retained lamellar structure. A rather uniform microduplex structure evolved after annealing at 1200 degrees C due to the accelerated kinetics of transformation at higher temperatures. The L1(2)/FCC phase showed the retention of the alpha-fiber components, while the B2 phase showed stronger ND-fiber after annealing, although inhomogeneities in texture existed.