Inhibiting Galvanic Corrosion of Aluminum Alloys Joined with Carbon Fiber Composites
Abstract
Basic and applied research will be conducted in this one-year project to test the hypothesis that modifying the surface of exposed c arbon fibers in carbon fiber reinforced polymer (CFRP) composites with aryl-substituted diazonium admolecules will significantly red uce the rate of galvanic corrosion of aluminum alloys when the surface finished alloys are joined to the composite. The two material s will be joined either by a metal fastener or a bonding adhesive in the tests to be conducted. Mono or multilayer adlayers of diazo nium molecules having different molecular structure will be formed electrochemically or spontaneously during solution exposure to th e exposed edge. The reduced rate of galvanic corrosion will result from a reduced rate ofdissolved oxygen reduction on the more nob le carbon fibers exposed in the CFRP. The admolecules, covalently bonded to the graphitic edge plane sites of the exposed fibers, wi ll block sites for O2 chemisorption. This is the first step in the reduction reaction in aqueous solution. The modification will for m a stable adlayer that is resistant to degradation during environmental exposure. Furthermore, the rate of galvanic corrosion will be further attenuated by finishing the aluminum alloy with a trivalent chromium process (TCP) or a non-chromium conversion coating. Chemically functionalized composites will be coupled with conversion-coated aluminum alloys and exposed to the two different accele rated degradation tests to learn how stable the adlayer is and how effectively it inhibits galvanic corrosion. This represents a new and novel approach for inhibiting oxygen reduction and, therefore, inhibiting galvanic corrosion on aluminum alloys when such alloy s are joined with a CFRP composite.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2021
- Source ID
- N000142112686
Entities
People
- Greg Swain
Organizations
- Michigan State University
- Office of Naval Research
- United States Navy