Investigation of Current-Carrying Oblique Impacts on the Copper–Aluminum Interface for Damage Characteristics

The gouging seriously affects the reliability and the life of railguns, and oblique impact is considered the main reason for gouging. In this article, a pulse power technology method for the current-carrying oblique impact using an electromagnetic (EM) repulsive disk was proposed. The strain rate of $1.5\times 10^{4}$ /s and the current density of $2.48\times 10^{9}$ A/m2 on the specimen were obtained by the numerical simulation. The dynamic impact damage and deposition characteristics of AA7075 and T2 copper contact interface under high current density and high strain rate were investigated. By comparing the microscopic characteristics distribution of the specimen profiles and surfaces under different current densities, the results are given as follows. The method is capable of generating gouging-like craters. The deformed area of the crater bottom exhibits obvious grain elongation and refinement. As the current increases, the depth of the crater and the thickness of the deformed layer gradually increase. The application of pulsed current stimulates aluminum deposition and the emergence of new phases. The influence of current on the mechanical properties is evident in the reduction of hardness and yield stress at the base of the craters.