Effect of pin penetration depth on the mechanical properties of friction stir spot welded aluminum and copper

The effect of pin penetration depth on the mechanical properties of friction stir spot welded (FSSW) aluminum alloy 1050 and pure copper has been investigated. For a certian tool geometry, constant tool rotation speed and penetration time, the materials have been friction stir spot welded in three different penetration depths, namely 2.8 mm, 4 mm and 5 mm. Tensile shear tests, microhardness measurements and micostruc-tural investigation have been carried out on the welded specimens in order to investigate the effect of penetration depth. 2.8 mm plunge depth has resulted in a weak joint, whereas 4 mm and 5 mm plunge depths offer acceptable tensile shear results. Presence of intermetallic phases had an influence on the tensile shear and hardness values. © Car Hanser Verlag, München.