Effect of long-term stress and temperature exposure on the fracture toughness of Ti-62222 alloy

Fracture toughness tests were conducted on a Ti-62222 (titanium alloy) shee t being considered for use in high temperature aircraft applications in the as received condition and after exposing the pre-cracked specimens to a su stained stress intensity, K, level between 55 and 60.5 MPa root m for 200 h at 350 degrees C. It was concluded that the fracture toughness does not de grade as a result of exposure to high temperature and the K levels in this material. The tensile strength in the exposed condition also remained the s ame as in the as received condition. (C) 1999 Elsevier Science Ltd. All rig hts reserved.