Use of Precracked Specimens in Selecting Heat Treatments for Stress Corrosion Resistance in High Strength Aluminum Alloys

Three techniques using precracked double cantilever beam (DCB) specimens have been employed to measure resistance to stress corrosion crack propagation as a function of the degree of overaging in the alloy 7075. Two techniques used single DCB specimens containing aging gradients along their lengths. The third technique used multiple DCB specimens, each one having a different heat treatment. All three techniques gave similar results, but stress corrosion resistance as a function of heat treatment was determined most rapidly using separate DCB specimens having different heat treatments. Data from this study suggest that DCB specimens would be useful in several other stress corrosion study areas, including that of thermomechanical treatments for aluminum alloys.