Fabrication, microstructure, and wear performance of WC-Fe composite/metal coating fabricated by resistance seam welding

WC-Fe composite/metal coatings consisting of a WC-Fe composite layer and a metal interlayer were successfully fabricated on an Al 6061 substrate by resistance seam welding. The microstructures and phase compositions of the WC-Fe composite/metal coatings with different WC particle sizes (nano, fine, and coarse) were investigated. The WC-Fe composite layer consisted of WC particles and a Fe-C-Si super hard alloy (SHA) component, whereas the metal interlayer was composed of SHA, FeAl3, Fe2Al5, and Al 6061. The surface microhardness of the WC-Fe composite/metal coating increased with increasing WC particle size. The wear performance of the coatings tested with different sliding distances is discussed in detail. Coating-C (coarse) showed the best wear resistance. The wear rates of both coating-N (nano) and coating-C decreased as the sliding distance increased, while coating-F (fine) demonstrated the opposite behavior. The wear mechanisms of the coatings were drastically different owing to the significantly different WC particle behavior at various sliding distances.