Effect of Hot Processing on Fracture Toughness and Crack Propagation Rate of Damage Tolerance TC21 Alloy

摘要

The rods of TC21 alloy with a diameter of 90 mm were produced by α+β and β processing. Crack propagation rate and fracture toughness of the rods were tested. Crack propagation behaviour with fine and coarse lamellar microstructures was studied. The results showed that material microstructure has an obvious effect on the crack propagation rate and fracture toughness, The rod produced by β processing has higher fracture toughness and lower crack propagation rate. The fine microstructure shows a lower crack propagation rates and a higher fracture toughness compared with that of the coarse microstructure. The stationary state propagation of crack is conducted in the form of striation mechanism, many fatigue striations were observed by scan electronic microscopy(SEM).