Influence of strain on the formation of cold-rolling and grain growth textures of an equiatomic HfZrTiTaNb refractory high entropy alloy

摘要

The effect of cold-rolling strain on the evolution of deformation and grain growth textures in an equiatomic HfZrTiTaNb refractory high entropy alloy (RHEA) was investigated. For this purpose, the development of microstructure and texture was compared in 50% and 90% cold-rolled materials. The development of deformation microstructure was accompanied by the formation of extensive deformation heterogeneities. The 90% cold rolled material showed ultrafine lamellar regions as well as regions severely fragmented by the fine scale deformation heterogeneities. The 50% cold-rolled material showed dominant ND-fiber (ND// 111 ), while the 90% cold-rolled material showed presence of both RD (RD// 110 ) and ND-fiber components. Profuse deformation heterogeneities presumably weakened the deformation texture considerably. The annealing texture of the 50% and 90% cold-rolled material showed stronger {111} 110 component. Comparison of the annealing texture of the 50% and 90% cold-rolled materials with other BCC HEA phases indicated much weaker texture. The annealing texture of the RHEA was not significantly strengthened by increasing cold-rolling strain, presumably due to the high density of deformation heterogeneities in the cold-rolled microstructure. Thus, deformation heterogeneities significantly influenced the formation of cold-rolling and annealing textures of the equiatomic HfZrTiTaNb RHEA.