Saltwater corrosion behavior of cold sprayed AA7075 aluminum alloy coatings. (January 2018)

• Record Type: Journal Article
• Authors: Ngai, Sieglind; Ngai, Tungwai; Vogel, Florian; Story, William; Thompson, Gregory B.; Brewer, Luke N.
• Is Part Of: Corrosion science. Volume 130(2018)
• Page Start: 231
• Page End: 240
• Publication Date: 2018-01
• Subjects: Aluminum -- Corrosion repair -- Cold spray deposition -- Pitting corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2017.10.033
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Corrosion behavior of cold spray deposited AA7075 was characterized by optical and scanning electron microscopy. Helium and Nitrogen were used as carrier gas and the resultant coatings were corroded in a salt water environment. Electrochemical and immersion testing was utilized. The Helium processed coatings corrosion resistance was superior to that of the Nitrogen processed coating. 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.