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Graphene Coating as a Corrosion Protection Barrier for Metallic Terminals in Automotive Environments
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on April 06, 2021 by SAE International in United States
Event: SAE WCX Digital Summit
Inside an automobile, there are hundreds of connectors and electrical terminals in various locations experiencing different corrosive environments. These connectors and electrical terminals need to be sealed, corrosion-proof, and provide good electrical contact for the lifetime of a vehicle. Saltwater and sulfuric acid are some of the main corrosion concerns for these electrical terminals. Currently various thin metallic layers such as gold (Au), silver (Ag), or tin (Sn) are plated on copper (Cu) terminals to ensure reliable electrical conduction during service. Graphene with excellent chemical stability can serve as a corrosion protective layer and prevent electrochemical oxidation of metallic terminals. In this work, the effects of thin graphene layers grown by plasma-enhanced chemical vapor deposition (PECVD) on Au and Ag terminals were investigated. Various machinal, thermal and electrical tests based on USCAR-2 specification were performed. In addition, a systematic corrosion study of various metallic terminals when exposed to saltwater, sulfuric liquid phase and the EIA 364-65B class IIA gas phase was performed. All cases tested confirm that the graphene layer substantially reduces the corrosion rate compared with terminals with no graphene coating. In addition, the resistance of the terminals remains almost unchanged when compared to that of bare terminals.