Failure Mechanism and Ultimate Strength of Friction Stir Spot Welded Al-5052 Joints under Tensil-eshear Loading

In this paper failure mechanism of a joint which was welded by friction stir spot welding method was studied. The 5052 aluminum joint was loaded under tensileshear condition.To find out failure mechanism, several tests were conducted such as: strainstress, macrography, and Vickers hardness. Results of strainstress test state the stages of failure and crack initiation and propagation. Macrography analysis was done in several stages with different penetration depths. It was shown that the material flow, the critical surface of the coupon, and the determined zones were more possible to generate crack. Finally, by using Vickers hardness test, the susceptible zones to crack generation and propagation can be specified.