COLD BUTT JOINING OF LIGHT METAL SHEET BY SHOT PEENING

Aluminum and magnesium materials are very attractive for light weight applications. However, their use is complicated by the fact that dissimilar metals are joined by fusion welding. In the present study, the cold butt joining of light metal sheet with dissimilar material sheet by shot peening was investigated. The shot peening process is widely used to improve the performance of engineering components. In this process the substrate undergoes a large plastic deformation near its surface when hit by many shots. The substrate material close to the Surface flows during shot peening. When the dissimilar metal sheets with notched edges are connected without a level difference and then the connection is shot peened, the sheets can be joined by the plastic flow generated by the large plastic deformation during shot peening. In this experiment, an air-type shot peening machine was used. The influences of peening time and shot material on joinability were mainly examined. The joinability was evaluated by tensile test. The joint strength increased with the amount of plastic flow. It was found that the present method can be used to enhance the butt joining of the light metal sheets with the dissimilar material sheets.