Fine-tuning of mechanical properties in V_(10)Cr_(15)Mn_5Fe_(35)Co_(10)Ni_(25) high-entropy alloy through high-pressure torsion and annealing

摘要

A V10Cr15Mn5Fe35Co10Ni25 (at%) high-entropy alloy (HEA) was subjected to high-pressure torsion (HPT) and subsequently annealed under different conditions to study Its microstructural evolution and mechanical properties. The HPT-processed sample consisted of a nanocrystalline structure with an average grain size of 30 nm. Annealing at 600 degrees C for 2min led to annealing induced hardening because of the formation of sigma phase, whereas samples annealed at higher temperatures showed a monotonous decrease in hardness because of dislocation recovery and grain growth. The average number of geometrically necessary dislocations decreased with increase in the temperature and duration time, indicating recovery of HPT-induced dislocations. Tensile properties indicated that the yield strength and ductility are notably influenced by the microstructure after annealing. The post-HPT annealing at 700 degrees C for 10 min resulted in an outstanding synergy of high tensile strength (similar to 1.54 GPa) and good elongation-to-failure (similar to 11%).