A novel design of VAlTiCrCu/WC alternate multilayer structure to enhance the mechanical and tribo-corrosion properties of the high-entropy alloy coating

Highlights: • The design of the VAlTiCrCu/WC multilayer structure improves the tribo-corrosion properties of the coating. • The VAlTiCrCu/WC coating with a modulation period of 17 nm has the best tribo-corrosion performance. • The VAlTiCrCu layer in the VAlTiCrCu/WC multilayer coatings has a typical BCC phase structure. In recent decades, high entropy alloys (HEAs) have given rise to much attention of researchers all over the world as emerging materials. VAlTiCrCu coating has good corrosion resistance, but its low hardness results in poor wear resistance. In this work, the novel VAlTiCrCu/WC multilayer coatings were fabricated by magnetron sputtering. The effects of modulation period (17 nm and 90 nm) on the corrosion resistance and tribological properties of the VAlTiCrCu/WC multilayer coatings were investigated. The results show that the VAlTiCrCu layer in the VAlTiCrCu/WC multilayer coatings has a typical BCC phase structure, and the WC layer significantly improves the mechanical behaviors of the HEA coating. In addition, a large number of interfaces in VAlTiCrCu/WC multilayers effectively inhibit the penetration of corrosive species into coatings, improving the tribo-corrosion performance. In comparison to the VAlTiCrCu coating, the VAlTiCrCu/WC multilayer coating with small modulation period (17 nm) has better adhesion, higher and more stable open circuit potential (OCP), and the wear resistance is increased by nearly 5 times.