Abstract
UDC 531/534
The effect of short-duration pulsed currents on closed high-current copper-coated aluminum contacts is studied numerically. Such current regimes are considered, which lead to significant contact area heating and cause melting and welding of the contacts. The influence of the copper coating thickness on the dynamics of contacts heating is estimated. As a result of the experimental study of the effects of initial short-circuit current on the high-current layered contacts, resistance to effects of such kind is analyzed by comparing copper-coatings manufactured using the sputtering and cladding techniques. The heating levels of the contact surface, at which it deteriorates when the welding break occurs, are determined. The deterioration of the sputtered coatings is shown to take place as early as at the stage of diffusion welding, while the clad layers are not significantly damaged at the same current levels.
Keywords: electric contacts, pulse heating, contact spot, constriction resistance, layered structure.