Corrosion behavior of WC-Co coatings deposited by cold gas spray onto AA 7075-T6

[Display omitted] •WC-12Co and WC-25Co coatings were sprayed on Al7075-T6 alloy by CGS.•Electrochemical reactions are O2 reduction on WC and Co oxidation from the binder.•WC-25Co coating showed the highest long-term anticorrosion performance in 3.5%NaCl.•WC-25Co coating showed corrosion after 3000 h in salt spray test with 5%NaCl. This work reports a morphological, mechanical, and corrosion resistance characterization of WC-12Co and WC-25Co coatings deposited by cold gas spray (CGS) onto AA 7075-T6 alloy. Cross-sectional images of the coatings revealed dense structures with low porosities. The coating thicknesses were 65 μm for WC-12Co and 118 μm for WC-25Co. XRD analysis showed that no fragile phases were formed in the coatings. SEM images and electrochemical results obtained after 700 h exposure to NaCl solution showed that WC-25Co exhibited better corrosion resistance performance. The WC-12Co and WC-25Co coatings withstood 1000 and 3000 h of salt fog spray test, respectively.