Fatigue crack propagation behavior of friction stir welded Al–Mg–Si alloy

Fatigue crack propagation (FCP) behavior of friction stir welded (FSWed) Al–Mg–Si alloy was examined with the fatigue crack growing either along the dynamically recrystallized zone (DXZ) at variable ΔK or perpendicular to the DXZ at a constant ΔK value of 7.5, 10 and 15 MPa√m. The FCP behavior of FSWed Al–Mg–Si specimen is substantially influenced by the presence of FSW zone, the trend of which is discussed based on residual stress measurement and fractographic observation.