2005 Volume 46 Issue 10 Pages 2211-2217
This paper investigated the effect of a tilt angle and a pin diameter of the tool on the tensile shear load of lap joints between A5083 aluminum alloy and SS400 steel produced by Friction Stir Welding. The main results obtained are as follows:
The joint shear strength could not be increased with the increase of a tool tilt angle due to the formation of intermetallic compound at the joint interface. The increase of a tool tilt angle caused the concentration of aluminum in the intermetallic compound increased, resulting in the decrease of the joint strength. The increase of a pin diameter of a tool also could not increase the shear strength of the joint due to a void defect and a thicker intermetallic compound formed at the interface. The size of the void increased as the pin diameter increased. The effect of a pre-hole, which was opened at the pin inserting position of an aluminum plate before welding, was investigated to obtain the higher shear strength of the joints. It was concluded that the joint interface temperature was slightly decreased and the thickness of the intermetallic compound at the interface decreased with the increase of pre-hole diameter. The optimal pre-hole indicated the shear strength of about 77% that of the aluminum base material. The interface microstructure examination showed no intermetallic compound was formed at the joint interface.