The correlation between fracture mechanics parameters and creep crack growth rate of Al 7050-T73651 at elevated temperature

• Non-linear fracture mechanics characterize of the Creep Crack Growth Behavior.
• The correlation between crack growth rate and c∗ could be expected to be better.
• By monitoring the resistance of the metal pattern, the progress of the crack is followed.
• Any load change may influence the crack propagation rate.
• Dimpled appearance of the fracture surface indicates ductile fracture.

It has been recognized that design against service failure in the airframe components, which will be subjected to temperatures more than room temperature, may require accurate prediction of crack propagation rate under creep conditions. In present work, a fracture mechanics approach is considered to study the crack growth rate of high-strength aluminum alloy 7050-T73651, which is of considerable interest for the aircraft industry. Tests were conducted under constant load condition on half inch thick compact tension, CT, specimens in air at 150 °C. During the tests, crack lengths were monitored by direct current potential drop, DC-PD, technique.