Effects of WC addition on the morphology, microstructure and mechanical properties of Fe50/TiC/WC laser claddings on AISI 1045 steel

Cermet coatings have shown great potential for surface quality improvement in medium carbon steels. However, full utilization of the properties is frequently restrained by defects such as crack, porosity and brittleness. To incorporate Fe/TiC and Fe/WC composites, surface quality of Fe50/TiC/WC ternary coatings on AISI 1045 carbon steel was evaluated by macroscopic morphology, microstructure and mechanical properties. The results show that with more WC in cladding powder, TiC particle is increasingly unmelted and retained in the coating, thereby forming more particle reinforced microstructure. Additionally, the coating microhardness gradually increases with WC fraction, while dilution, porosity and wear resistance are correlated by concave functions. It is also found that appropriate addition of WC can effectively blunt sharp edges of TiC particles, which helps mitigate stress concentration. The optimized overall performance of Fe50/TiC/WC coating with 10% WC has a minimized porosity, three-fold microhardness (about 56.1HRC) and 1.5% wear volume compared to the substrate.