Wear and contamination of electroplated gold films in line contact

The tribological characteristic of an electroplated gold contact in a sealed relay was investigated. The morphology and contamination of cylinder flat contacts under the actions of impacting and sliding in no- and low-load conditions were studied. The experimental results show that impact wear dominates at normally closed (NC) contacts, while sliding wear dominates at normally opened (NO) contacts. The major contact wear process is adhesion for a plated gold in-line contact. Adhesive wear can operate in both impact and sliding actions. Due to severe wear, the substrate materials are exposed, and therefore, contaminations such as oxidation, sulfidation, chlorination, and polymerization take place on the contact zones. It is the wear and contamination which cause the contact resistance to rise, and which then lead to contact failure