Effect of Heat Treatment on Microstructure and Mechanical Properties of Ti5211 Plates

The effects of recrystallization annealing temperature on the microstructure and mechanical properties of Ti5211 titanium alloy plates are studied. The results show that with the increasing of annealing temperature, primary α phase tends to change from long columnar to be equiaxed, and the secondary α phase precipitates gradually and grows up. After being annealed at 950 ℃, the microstructure is a bimodal structure with lamellar α phase, and after being annealed at 965 ℃, it is an equiaxed structure. With the increasing of annealing temperature, the room temperature strength decreases, the room temperature plasticity shows no obvious change, and the impact toughness first increases and then decreases.