(V) Cold Spray for In-field Corrosion Repair

Corrosion mitigation techniques that may be applied in the field is an area of need for the corrosion industry. Moreover, repair and lifetime extension continues to be a pressing topic as aging infrastructure approaches the end of useful design life. The portability of cold spray systems presents an opportunity to replace lost metal and repair damaged assets with metallic coatings in the field to mitigate susceptibility to further corrosion degradation. Moreover, it may be possible through powder stock design/choice to globally increase the corrosion resistance after deployment through cold spray coatings applications.

This program seeks to understand the applicability of cold spray to in-field repair of damaged assets, specifically those structures that have suffered deleterious corrosion. Patch repair via cold spray presents an opportunity to avoid expensive tear down and rehabilitation. However, differing metallic compositions between substrate and coating and the formation of discontinuous interfaces at the edges of the patch may serve to simply change the corrosion mechanism at play. This work details the characterization of cold spray coatings in a patch repair paradigm for potential galvanic interactions, resistance to pitting in marine environments, the nature of the bond at the diffuse edges of repair patch borders, and the propensity for differential aeration/crevice formation between substrate and applied coating.

It is paramount for the adoption of new repair strategies that adequate characterization is performed to ensure that solving a problem with cold spray doesn't create additional issues unique to cold spray coatings application.