Kinetic Metallization Repair of Alclad

Cladding is a common method of providing corrosion protection of aluminum alloys, which forms an anodic layer in direct and intimate contact with the alloy sheet during cold roll processing. A structural aluminum alloy is clad in a thin layer of a higher purity alloy that is more galvanically reactive. Common examples include 1230 clad on 2024, and 7072 clad on 6061 and 7075. If this clad layer is damaged or removed the underlying structural alloy is exposed and susceptible to corrosion and/or stress corrosion cracking. Kinetic Metallization, a low temperature deposition technique compliant with MIL-STD-3021, enables repair or replacement of worn or damaged clad layers. Aluminum or Al-Trans® coatings are deposited as a new clad coating, and can be subsequently polished to the same mirror finish as the original clad surfaces. This paper presents the techniques developed for repairing worn or damaged Alclad surfaces using the economical Kinetic Metallization process and the qualification tests performed to date for various feedstock powder formulations.