Investigation of the Repair of Aluminum Cladding Using Supersonic Cold Spray for Corrosion Protection

Aluminum cladding has long been used as a non-structural coating for high strength aluminum alloys as a protective measure to reduce or prevent corrosion. It can also be brightly polished as an attractive and conductive cosmetic finish. High impact and wear areas, however, can be damaged by foreign objects, debris, or repeated polishing, which can expose the underlying material to corrosive elements and lead to an unsightly appearance. There exists therefore the need to repair areas where cladding has been lost, restoring its original finish and corrosion protection, without altering or affecting the underlying parent material. Supersonic cold spray technologies have been under increasing development lately as a method of metallurgically bonding metal particles to a substrate without heating of the substrate itself. By accelerating aluminum powders to supersonic velocities it is possible to reapply a thin layer of cladding material to an aluminum part, which can then be subsequently ground and polished to restore the original clad finish on the part. An evaluation of the integrity and cosmetic appearance of the polished cold sprayed clad layer, as well as its performance under alternate immersion in a solution of NaCl, compared to parent clad material is presented and discussed.