Hardness and corrosion properties of AA7075 aluminum alloy coated with WC-Co by HVOF

Abstract In this study, AA7075-T6 aluminum alloy substrates were coated with WC-Co by the high velocity oxy-fuel (HVOF) method. The coatings were applied in two and four layers to surfaces with three different roughnesses. The effects of WC-Co coating applied to the AA7075 aluminum surface on the hardness and corrosion properties of the alloy were examined. The corrosion properties of uncoated and WC-Co coated aluminum alloy samples were determined in salt water environment by potentiodynamic corrosion tests. Additionally, microstructure and XRD examinations of the samples were performed. The surface hardness of WC-Co coated samples increased by up to 140 %. According to the results of corrosion tests, it was determined that the WC-Co coating applied to the surface of AA7075 aluminum alloy improved its corrosion resistance by reducing the corrosion rate of the alloy. The best corrosion resistance was obtained in four layers of coating on the sample with the smallest surface roughness.