Measurement of the temperature rise at the welding surface of different metal specimens joined by a 15 kHz ultrasonic butt welding system

Abstract

The temperature rise at the welding surface of different metal specimens joined by a 15 kHz ultrasonic butt welding system is studied. The welded zone of the ultrasonic welding is limited to a very thin area and a clear melted structure cannot be observed and also the temperature rise at the welding surface cannot obtained by clearly measured. Temperature rises at the welding surfaces of different metal specimens are measured directly by the thermoelectromotive force between them, using a system with a small time constant. The temperature rises are measured using a 15 kHz ultrasonic butt welding with which it is possible to join the welding specimens directly end to end. Aluminum, copper and steel plates of 6mm thickness were successfully joined end to end. The measured temperature rise rate is very high at the initial welding stage and decreases, or the temperature saturates, as the welding process progresses and the welding strength increases.