The automotive connector: The influence of powering and lubricating a fretting contact interface

Abstract

The increasing amount of telematic and other electronic systems in the modern motor vehicle demands higher performance and reliability in ever decreasing space. Over many years, connector technology has advanced but is still regarded as the weak link in the reliability chain. Fretting corrosion is thought to be the main failure mechanism causing intermittent high contact resistance. A low-frequency fretting apparatus is used in this study to induce fretting corrosion on contact samples. Low frequency is used to simulate the effect caused by different thermal expansion of connector components. Powering the contact interface under these fretting conditions delays the onset of high contact resistance. Joule heating is expected to accelerate surface oxidation, but electrical breakdown of films dominated at the levels studied (2 A, 12 V open circuit). Lubricating the interface also improves performance which is shown to be due to at least three contact enhancement mechanisms: wear reduction, oxidation retardation and improved debris dispersal.