Effect of Annealing on Microstructures and Mechanical Properties of CrCuFeMnTi High Entropy Alloy

In order to investigate the effect of annealing treatment on microstructures and mechanical properties of CrCuFeMnTi high entropy alloy, a as-cast CrCuFeMnTi alloy ingot was prepared by vacuum arc melting under the argon protection, and then the microstructures observation and mechanical properties testing of alloy samples under annealing treatment at different temperatures were performed. The results show that the as-cast CrCuFeMnTi alloy is composed of a hexagonal close packed phase and a face centered cubic solid solution, and typical microstructures with dendrite and interdendrite phases are observed. There is mainly element diffusion and morphology homogenization when the annealing temperature is under 750 degrees C, and the hexagonal close packed phase will transform into body centered phase after the alloy is annealed at 900 degrees C. Element diffusion causes the phase transition and controls it. The hardness and strength of the alloy are all improved when the alloy is annealed below 750 degrees C; meanwhile, all the fracture exhibits a brittle character.