Ultrasonic butt welding of aluminum and stainless steel specimens using a 15 kHz welding system

The welding characteristics of aluminum and stainless steel plate specimens of 6 mm thickness joined by a 15 kHz ultrasonic butt welding system are st udied. Both materials are anticorrosive and have various applications due t o small deformation at the welded part. The specimens without special surfa ce treatment were joined end to end with the weld strength of 100 MPa. The hardness of aluminum decreases at the area close to the welded surface, whi ch is the Same as-in other materials. The hardness of stainless steel incre ases by approximately 20% near the welded surface. The increase in hardness due to ultrasonic vibration was observed for the first time though only th e decrease in hardness was mentioned in previous studies.