Experimental study of the effect of a contact conditioner on sliding electrical contacts

Abstract

The Electro Magnetic Rail Gun on board with Navy consists of high current carrying copper rails. Aprojectile carrier or armature slides over these rails with very high velocities. Inefficient sliding contact conditions between these two produces high rail wear. This restricts life of rails to a very less number of shots than expected. This research aims at finding effect of solid lubricant contact conditioner (SLIC) on sliding electrical contacts, which can help in predicting sliding interface behavior with and without the use of SLIC. The findings will ultimately help in increasing the rail life. The actual working conditions are simulated with an instrumented Pin-on-Disc setup. The setup is used to perform Static, Circular and Spiral sliding tests to estimate key quantities of interest such as contact resistance, coefficient of friction, amount of material transfer and wear. Tests are carried out at different current densities and contact force combinations, with and without use of conditioner. Test results show, use of solid lubricant conditioner reduces coefficient of friction by half in sliding, decreases amount of material transfer or wear but increases contact resistance by small amount.