Saltwater corrosion behavior of cold sprayed AA7075 aluminum alloy coatings

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.