Abstract
Electromagnetic welding is classified as a high energy rate welding, and hence, the feasibility of this welding depends, in principle, on the velocity of flying body at the time of collision, as experienced well in the case of explosive welding. The authors pointed out in this paper that its acceleration could be an important factor in this welding, as well as its velocity. The deformation test under a high velocity on the aluminum tube and the welding test on the joint of tube and core brought the following conclusions.
(1) Under the high strain rate condition of electromagnetic welding, the increment of flow stress caused by the strain rate hardening should be accounted, other than that by the strain hardening, because the former increased very significantly with increasing the strain rate.
(2) Both the velocity and acceleration of flying tube controlled the feasibility of welding; the larger the acceleration was, the smaller became the velocity required for obtaining the welding joint.
(3) The result of (2) suggested that the welding was performed when the sum of the kinematic energy and strain energy given by the pressure at collision reached a critical value.
