Evaluation of Aluminum/Ceramic Coating on Fasteners to Eliminate Galvanic Corrosion 860112

This paper addresses the use of novel aluminum-filled inorganic coatings on plain carbon steel or stainless steel fasteners in order to eliminate galvanic corrosion in structural assemblies incorporating dissimilar metals. These coatings are described and compared with zinc plated fasteners and other metals in a galvanic series. In environmental testing, stainless steel fasteners and carbon steel fasteners coated with zinc and aluminum-filled coatings, are coupled with aluminum, tin, copper, and 300 series stainless steel. The results of these tests indicate that this sacrificial aluminum/ceramic coating system limits corrosion of steel fasteners more effectively than zinc platings. Moreover, when active or passive metals, including aluminum, tin, copper, and stainless steel, were joined using fasteners coated with the aluminum-filled material, corrosion of both fasteners and structural components was controlled more effectively than when zinc plated or stainless steel screws were used.