Effect of oxide array on the fatigue property of friction stir welds

The fatigue behaviour of single-sided friction stir (FS) butt welds containing oxide array was investigated. The oxide array makes cracks initiate easily under fatigue loading, and has a deleterious effect on the fatigue properties of FS welds. The fatigue characteristic values of FS welds with oxide array have been decreased by 35% for 5083 welds and 55% for 2024 welds at 2 × 106 cycles. The fatigue lives of FS welds with oxide array were 20–40 times shorter for Al 5083 welds and 30–80 times shorter for Al 2024 welds than those of sound welds under the stress ratio R = 0.1.