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 eect caused by dierent 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 ®lms 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.

Fretting corrosion of lubricated tin‐plated contacts

“…Hence, it is evident that lubricant used in the present study is very effective in delaying the fretting wear during the initial stages and in preventing the oxidation and, accumulation of oxidation products at the contact zone in the later stages. Reduced wear due to decreased metal-metal contact and retardation of surface oxidation for lubricated contacts has also been observed earlier many authors (Antler, 1985;Abbott, 1996;Swingler, 2000). The observations of the surface analytical studies and the observed changes in the contact resistance of lubricated tin plated contacts ( Figure 3) correlate very well.…”

“…Lubrication has also been shown to reduce or eliminate fretting corrosion (Swingler, 2000) and is considered as a possible solution for preventing fretting corrosion (van Dijk and van Meijl, 1999). A variety of lubricants, namely, polyphenyl ethers, natural and synthetic hydrocarbons, several types of esters, polyglycols, some fluorinated materials, silicone and some proprietary formulations were evaluated for their suitability for connector applications (Freitag, 1977).…”

“…The effect of lubricants on electrical contacts, evaluated using either an existing connector or a rider‐to‐flat configuration, clearly reveals a significant improvement in wear and corrosion resistance (Antler, 1987a, b, 1996; Abbott, 1996). Lubrication has also been shown to reduce or eliminate fretting corrosion (Swingler, 2000) and is considered as a possible solution for preventing fretting corrosion (van Dijk and van Meijl, 1999). A variety of lubricants, namely, polyphenyl ethers, natural and synthetic hydrocarbons, several types of esters, polyglycols, some fluorinated materials, silicone and some proprietary formulations were evaluated for their suitability for connector applications (Freitag, 1977).…”

No Fault Found events in maintenance engineering Part 2: Root causes, technical developments and future research

“…Such manifestations fracture the solder contacts and instigate intermittent faults. Electrical intermittency is also caused by contact fretting [15,20]. Fretting corrosion occur particularly in tin plated contacts, as a degradation mechanism caused by the presence of humidity which oxidizes the metal-metal interface.…”

Relief making on bearing sleeve surface by eccentric burnishing

“…It should not be too big lest the area should lose its planovertical nature and in order to avoid a decrease in its bearing capacity beyond the allowable limit. It follows from different investigations that (a lot depends on the contour of a particular friction spot) the coverage degree, while the necessary load-bearing capacity is ensured, should not be greater than 25-48% (Swingler, 2000) as its increase does not considerably improve lubrication and may even cause the above mentioned negative effects reflected by increased wear.…”