Influence of mineral silicon containing deburring media on contact resistance of fine silver rivets

Embedment of mineral silicon (SiO/sub 2/) introduced by deburring electrical contacts inhibits metallic conduction. The concentration of mineral silicon (SiO/sub 2/) on fine silver contacts submitted to deburring in an open tumbler and harperizing for specific time intervals is investigated to assess the factors contributing to low contact resistance in dry circuit applications. When arcing, quick surface degradation results at contact pressure of 50 g (0.5 N). Low contact resistance in dry circuit applications is achieved even when contacts are severely contaminated with mineral silicon (SiO/sub 2/) at contact pressure less than 50 g (0.5 N). Further reduction in static contact resistance is achieved by chemically etching contaminated rivets. The opposite findings are obtained when contacts are subjected to 12.5 VDC and 0.5-A load. Low contact resistance in dry circuit applications and erratic millivolt drop during electrical switching are explained as interactions among mineral silicon (SiO/sub 2/) concentrations before and after chemical etching.<>