Electrical resistance of silver-silver contacts under vibrational loads

Abstract

Abstract Accelerated life tests on silver-silver contacts vibrated at 500 Hz were conducted. When, for a period of 12 h, the applied force was 10 + 5 sin (2 π 500 t ) N, the electrical contact resistance decreased, but the reverse occurred when the applied force was 1+0.5 sin (2 π 500 t ) N. These phenomena are attributed respectively to increasing compliance and work hardening of the asperity tips. After sufficiently long periods ( ~100 h) the resistances of all the tested contacts between these soft surfaces decreased compared with their initial values, and the eventual static load-unload curves obtained after completion of the vibration exhibited no hystereses. No changes in the c.l.a. surface roughnesses of the contacting surfaces were detected even though large changes in the electrical contact resistance occurred.