Strain-path controlled microstructure, texture and hardness evolution in cryo-deformed AlCoCrFeNi 2.1 eutectic high entropy alloy

Abstract

The effect of strain path on microstructure, texture and hardness properties of AlCoCrFeNi 2.1 eutectic high entropy alloy containing ordered FCC (L1 2) and ordered BCC (B2) was investigated. The EHEA was cryo-rolled using UCR, MSCR (during which the samples were rotated by 90° around the ND between each pass) and TSCR(45°) (in which the samples were deformed by unidirectional rolling to half of the total strain and then diagonally rolled for rest half of the strain). The UCR processed material showed a rather heterogeneous microstructure. The textures of the L1 2 /FCC and B2 phases in the MSCR processed material agreed with the cross-rolling texture of the corresponding single phase materials, while the texture of the two phases in the TSCR(45°) processed materials appeared rather weak. Upon annealing at 800°C, the UCR processed materials showed a novel heterogeneous microstructure, while the MSCR and TSCR(45°) processed materials revealed microduplex structure. The heterogeneous microstructure was replaced by the usual microduplex structure at higher annealing temperatures. The annealing texture of the L1 2 /FCC phase showed the presence of α-fiber (ND//<011>) components while the B2 phase showed strong ND-fiber (ND//<111>) components. The UCR processed material with novel heterogeneous microstructure showed much greater hardness as compared to the MSCR and TSCR(45°) processed materials. The present results indicate that strain path exerted significant influence in controlling microstructure, texture and hardness properties of EHEA.

Effect of cross cold rolling and annealing on microstructure and texture in pure nickel

“…The formation of weaken cube texture was also reported in various copper and copper alloys subjected to cross-rolling and annealing as well as the friction stir welding and the subsequent cooling [11][12][13][14][15]. In addition, the development of unusual recrystallization textures was reported in duplex alloys and high entropy alloys, and the results evidenced the different mechanism were contributed to the recrystallized textures [16][17][18]. In the present work, there are two concerns to be paid attention in the cross-rolled and annealed pure nickel, which are important for enriching the mechanism of recrystallization.…”

Strength–Ductility Synergy in High Entropy Alloys by Tuning the Thermo-Mechanical Process Parameters: A Comprehensive Review

“…In addition to temperature, the parameters like amount of total strain, strain path, symmetricity of rolling (symmetric/ asymmetric rolling), etc. also play an important role in ascertaining the final properties of an HEA [40][41][42] . During the heat treatment of the HEA, the annealing temperature primarily dictates microstructural evolution 43 .…”

Microstructure study of cold rolled Al0.32CoCrFeMnNi high-entropy alloy: Interactions between recrystallization and precipitation

“…The presence of the B2 phase induces a strengthening of the material that can be at the expense of ductility when its formation is not well controlled. While many studies have focused on as-cast materials [1,23,25,28,30,32,43,46,[49][50][51]55,[61][62][63][64][65][66][67][68][69][70][70][71][72][73], several recent studies used thermomechanical treatments with the objective of better controlling their final microstructures [31,[74][75][76][77][78][79][80][81][82][83][84][85][86][87][88]. For example, the recent work of R. Banerjee et al [81][82][83][84][85][86]…”