On Peculiarities of Welding and Destruction of the Surface of High-Current Layered Contacts by Pulsed Currents

Resumo

Numerical modeling of the impact of short-duration pulsed currents on closed high-current copper- coated aluminum contacts is carried out. The modes of the current effects are studied which induce a significant contact area heating and cause melting and welding of the contacts. The influence of the copper coating thickness on the dynamics of the heating of the contacts is determined. In the course of the experimental study of the action of the shock short-circuit currents on the layered contacts, a comparative analysis was carried out of the resistance of the copper coating to such actions. The latter was manufactured using the sputtering and plating techniques. The heating levels of the contact surface, which cause its destruction during the breakup of the occurring thermal bonds, are determined. The destruction of the sputtered coating is observed to occur as soon as the stage of the diffusion welding begins, whereas the plated layers are not significantly damaged at the same current levels.