Graphene Coating as a Corrosion Protection Barrier for Metallic Terminals in Automotive Environments

Abstract

<div class="section abstract"><div class="htmlview paragraph">Inside an automobile, hundreds of connectors and electrical terminals in various locations experience different corrosive environments. These connectors and electrical terminals need to be corrosion-proof and provide a good electrical contact for a vehicle’s lifetime. 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 with a nickel (Ni) layer on copper alloy (Cu) terminals to ensure reliable electrical conduction during service. Graphene due to its excellent chemical stability can serve as a corrosion protective layer and prevent electrochemical oxidation of metallic terminals. In this work, effects of thin graphene layers grown by plasma-enhanced chemical vapor deposition (PECVD) on Au and Ag terminals and thin-film devices were investigated. Various mechanical, thermal/humidity, and electrical tests were performed. In addition, a systematic corrosion study of various metallic surfaces when exposed to saltwater, sulfuric liquid phase, and EIA 364-65B class IIA gas phase was performed. All tested cases confirm that graphene layer substantially reduces corrosion rate compared with the samples with no graphene coating. The resistance of the metallic terminals remains almost unchanged when compared to that of bare terminals.</div></div>