Corrosion Performance of Different Aluminum Alloy Deposits Fabricated by Lateral Friction Surfacing

Friction surfacing technique is a thermo-mechanical approach for metallic deposition, suitable for a broad range of materials and applications. Friction surfacing can be employed for various industrial purposes such as coating, welding, repairing defective parts, surface hardening, and improving corrosion performance. In this technique, frictional heat generated at the interface of the consumable tool and substrate results in a severe plastic deformation at the end of the rod, enabling the deposition of a consumable material on the substrate surface. In this investigation, a novel method in friction surfacing, lateral friction surfacing, is employed to deposit the aluminum coatings. In this novel approach, the side of the consumable tool is pressed against the surface of the substrate, and the material transfer happens from the lateral surface of the tool. This technique provides extremely thin and smooth deposits, which are more consistent compared to the conventional approach of friction surfacing. Moreover, this technique enables fabricating of deposits in lower temperatures, lessening the thermal impacts on the microstructures and mechanical properties of the deposits. In this investigation plates of 1018 mild steel were partially coated with various aluminum alloys and corroded in an accelerated corrosion test chamber. The corrosion performance of the partially coated sample was evaluated by mass loss measurement. It was found that AA5086 offered the most corrosion protection. After 13 cycles of GM9540P test, equivalent to approximately 3½ years exposure at a mild/moderate marine site in Hawaii, almost all of the deposited aluminum was corroded off.