Microstructure and mechanical properties of FeCoCrNiMo0.1 high-entropy alloy with various annealing treatments

Abstract

The effect of annealing treatments on the microstructure, mechanical properties and corrosion behaviour was thoroughly investigated in this study. The results indicated that the annealing treatments largely affected the grain size, leading to different mechanical properties and deformation characteristic. The strength-ductility combination of FeCoCrNiMo0.1 alloy at 77 K significantly increases compared with that at 293 K. At a strain of 35%–45% and a stress up to 1173–1210 MPa, the deformation twins are activated at 77 K, which are introduced to accommodate the deformation with the dislocation activities. Moreover, the corrosion resistance of the alloys with different annealed states was preliminarily evaluated by potentiodynamic polarization curves. In general, the alloys annealed at 900 °C for 30 min and 900 °C for 60 min showed improved mechanical properties and corrosion resistance. A practical heat treatment process is provided herein, and the correlation between the heat treatment process and performance is further established, paving the way for the design of HEAs.