Effects of Quasi-beta Forging and β Heat Treatment on Microstructure and Fracture Toughness of TC11 Titanium Alloy
Effects of quasi-beta forging and β heat treatment for TC11 titanium alloy on microstructure and fracture toughness were investigated.The results showed that the fracture toughness of TC1 1 titanium alloy after quasi-beta forging and β heat treatment significantly improved compared to Widmanstatten microstruc-ture.Elongation rate increased by about 50%,section shrinkage increased by about 20%,and the frac-ture toughness significantly increases by about 20%.The reason was that quasi-beta forging had changed the precipitation morphology of lamellar a-phase and contributed to the misorientation of colony,the coordi-nation of the microstructure to resist the expansion of the cracks was better,which increased the fracture toughness.While the Widmanstatten microstructure mainly increased the crack-extension tortuosity with grain boundaries and large secondary α-phases.