Butt Joining of Dissimilar Thin Sheets by Shot Peening

There are many techniques for joining dissimilar materials to thin sheet, such as welding and friction stir welding. In the present study, we attempted butt joining of dissimilar materials using shot peening. Test materials were pure copper, mild steel, and pure aluminum sheets with thicknesses of 1 to 1.4 mm. Resin sheets were also used. The micro-shot and the air-type machine were used to perform peening on the butt joints. The peening pressure was 0.6 MPa, and the peening time was 5 to 100 seconds. The butt joints had an uneven shape. Specifically, the uneven shape was a tapered trapezoid. The peening was performed on both sides of the joint. The bondability was evaluated by tensile test. The joints were observed under a microscope. The impact of the fine particles caused plastic deformation of the surface layer of the joint, resulting in a caulking effect. It was found that it is possible to join dissimilar materials using shot peening.