Properties and character of crack growth in extrusions of an Al-Cu-Li alloy

Tests of specimens of Al-Cu-Li alloys have shown that fatigue cracks in these materials sometimes grow in directions different from the applied load. This article examines the effect of different stages of aging on the rate of fatigue-crack growth (FCGR) and direction of crack propagation in tests conducted on extrusions of alloy 1450 to determine fracture toughness (KID) and resistance to fatigue.