Saltwater corrosion behavior of cold sprayed {AA7075} aluminum alloy coatings
By Ngai, Sieglind; Ngai, Tungwai; Vogel, Florian; Story, William; Thompson, Gregory B.; Brewer, Luke N.
Published in Corrosion Science
2018
Abstract
Salt water corrosion behavior of cold sprayed {AA7075} is examined. Coatings on AA7075-T651 substrates were prepared by cold spraying {AA7075} powder using He and {N2} as carrier gases. Severe plastic deformation is only observed in the helium sprayed samples. Electrochemical experiments performed on the coatings reveal inferior corrosion resistance of the nitrogen sprayed samples, although both coatings exhibit lesser corrosion resistance than the AA7075-T651 substrate. The localized corrosion response is qualitatively different between the three materials with large scale pitting in the plate material, limited pitting in the helium sprayed material, and microscale crevice corrosion in the nitrogen sprayed material.