Residual Stress and Microstructure Effects on Fatigue Crack Growth in AA2050 Friction Stir Welds

摘要: Abstract In this work, results of a study conducted on fatigue crack propagation in friction stir welded AA2050 and the effects FSW induced residual stresses, as well changes microstructure, are presented. Longitudinal stress profiles across butt 2050 plates were determined using cut compliance technique growth testing was compact tension specimens machined from welds. Tests performed with propagating nominally perpendicular to weld constant, applied, cyclic, intensity factor. Two different material tempers investigated both cases stresses found have major effect propagation. It shown that compressive present vicinity weld, leading closure decrease rate approaches weld. Once nugget, increases. This increase is believed be linked part tensile but also microstructural when grows through recrystallized nugget. observed other mechanisms, such oxide-induced may affect behavior FSW’s. methods predict rates zones attempted: by effective factor, Δ K eff , obtained during testing.