1990 Volume 8 Issue 2 Pages 185-191
Aluminum specimens consisted of couples of tubes and cores were welded by electromangetic welding at elevated temperatures up to 500°C. An equipment with capacitor of 470, UF and nominal voltage o f 10 kV was used. To discuss the results of welding test, the collision velocity and the collision acceleration were evaluated by the deformation analysis on specimen tubes at elevated temperatures. Several flow stresses of aluminum required for the analysis were obtained by the deformation tests on specimen tubes and the hardness tests on deformed ones. The following results were obtained. (1) The electromagnetic energy required for welding at 500°C amounts to about half of that at the room temperature. (2) Althouhg the strain rate dependance of flow stress of aluminum decreases with a raising temperature, the flow stress itself decreases with the temperature, because the strain hardening is remarkably reduced with the temperature. (3) The favorable effect of heating the specimen is caused by two factors, i) the increases of collision velocity and collision acceleration of tube, ii) the decreases of the critical collision velocity and the collision acceleration required for welding. The fractions of their contributions are 30%(i) to 70% (ii).