The effects of annealing on severely cold-rolled equiatomic HfNbTiZr high entropy alloy

In this study, the effects of annealing on mechanical properties and phase evolution of 80% cold-rolled equiatomic HfNbTiZr high entropy alloy (HEA) are studied. A single BCC-phase solid solution is identified in the as cold-rolled and the recrystallized state at above 700 degrees C, and its hardness increases as the annealing temperature increases. However, the HEA still follows the Hall-Petch equation according to tensile tests. When the HfNbTiZr HEA is annealed at 450 degrees C, hardness would increase, while the hardening effect on 550 degrees C annealed specimens is not so pronounced. The age hardening effect is mainly associated with the formation of HCP precipitates.

Automated summary

The study found that annealing of HfNbTiZr HEA can increase its hardness, and the hardening effect is mainly associated with the formation of HCP precipitates.