Fracture toughness and fatigue crack propagation behavior of 8090 Al-Li alloy

We present results of fatigue tests of high-strength 8090 Al-Li alloy and data on its fatigue crack growth resistance. High strength combined with fairly high crack growth resistance and endurance limit results in much better service characteristics compared to other high-strength aluminum alloys. We discuss results of tensile and impact tests of Charpy specimens and the critical values of theJ-integral andK1c for 10-mm-thick specimens in the T-L and L-T orientations subjected to complete and partial aging. The experimental results are compared with published data for 8090 and other high-strength aluminum alloys. We suggest a numerical method for the evaluation of fatigue strength according toda/dN-ΔK diagrams.