초록 |
We conduct a series of fretting corrosion tests on tin-coated electric contact to evaluate the effects of lubricant on fretting corrosion behavior. We perform these tests with a constant contact force at 25 #x2103; 50 #x2103;, 75 #xB0;C, and 100 #x2103;. In the tests with a span amplitude of 30 #x3BC;m, we could not determine the conventional behavior of the first, second, and third stages of the change in electric resistance during fretting corrosion and observed that the contact resistance continuously increases with the cycles. This behavior is due to the fact that the generation of oxides on the tin-coated contact is controlled and stabilized by the presence of lubricant. SEM observations on samples with a span amplitude of 77 #x3BC;m at all testing temperatures confirm that there is less oxide debris on the fretting damaged surface. Hence, for tin-coated electric connector, the effect of lubrication on the lifetime of the electric contact increases as the fretting span decreases and testing temperature increases, compared to those for connector without lubricant. Especially, for a specimen with a span amplitude of 30 #x3BC;m at 100 #x2103;, the increment in contact lifetime due to lubricant is found to be more than 20 times, compared to that without lubricant. |