Microstructure and mechanical properties evolution of B_1.5(CrFeNi)_98.5 medium-entropy alloy during recrystallization annealing

A cold-rolled B 1.5 (CrFeNi) 98.5 medium-entropy alloy was annealed at 600–1000 °C for 1 h to investigate the microstructure and mechanical properties evolution duding recrystallization annealing process. The as-cast alloy exhibited an FCC + Cr 2 B dual-phase structure and dendritic microstructure. The annealed alloy exhibited a typical bimodal grain structure. Massive BCC-structured precipitate with a nano-scale formed in FCC pahse, whose content reached the peak around 800 °C, and then almost disappeared at 1000 °C. The yield strength of the alloy reduced from 1225 MPa in cold-rolling state to 330 MPa when annealed at 1000 °C, and the elongation raised from 2.4% to 33.8%. The alloy annealed at 800°C displayed a good strength-plasticity balance with a yield strength of 601 MPa and an elongation of 20%.