|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Coatings and Surface Engineering for Environmental Protection
||C-4: Corrosion Behavior of Aluminum Alloy AA7075 Cold Sprayed Coatings
||Ozymandias Agar, Anne Chappell Alex, Luke N. Brewer
|On-Site Speaker (Planned)
This presentation will discuss the corrosion behavior of cold spray deposited AA7075 coatings. Cold spray is often used to repair components damaged by corrosion, and so it is important to examine the corrosion behavior of the repair material and coatings. AA7075 deposits were produced using a high-pressure cold spray deposition system with both helium and nitrogen gases. Helium-sprayed materials had very high density, while increasing nitrogen content in the spray gas caused increasing, interconnected porosity. The electrochemical characteristics of these coatings were measured in an immersed, simulated salt water (3.5 wt% NaCl) environment. The helium-sprayed material was slightly more active than AA7075-T651 plate, while the nitrogen-sprayed material had a significantly higher corrosion rate. Immersion testing in still water for one week showed classic pitting behavior for the helium-sprayed material with slightly less pitting than wrought plate. The nitrogen-sprayed material exhibited significant micro-crevice corrosion because of its microscale porosity.
||Planned: Supplemental Proceedings volume