Effect of displacement and humidity on contact resistance of copper electrical contacts. (March 2016) - Sung, I.H.
Abstract: The effect of displacement and humidity on fretting-induced instability of electrical contact resistance ( R c ) was studied. A fretting tester was used to examine R c in partial and gross slip modes. Under the partial slip regime the contact failure was susceptible to the displacement and moisture effectively increased contact stability, which was pronounced at smaller displacements. In the gross slip mode, however, humidity effect was relatively small. The early contact failure at low humidity was attributed to the wear debris agglomeration within the sliding interface, suggesting a high propensity of electrical contact failure at dry conditions. Highlights: The effect of humidity and displacement on fretting induced electrical contact failure was studied. Humidity effect was pronounced at small displacements due to effective removal of debris. Premature contact failure was found at low humidity and with large displacements. Moisture reduced wear debris pileup, producing a smooth contact area with more electrical junctions. Our results suggested a high propensity of electrical contact failure at dry conditions.