Development and Application of WC-Cr3C2-Ni Coating with High Impact Resistance

Abstract

Abstract The aim of this study was to investigate a new generation of agglomerated and sintered composite (WC, Cr3C2, Ni and Cr) powders for improved impact and wear resistance. The poor impact resistance of conventional WC cermet coatings, such as WC-20%Cr3C2-7%Ni, WC-10%Co-4%Cr and WC-12%Co, has so far hindered their use in new industrial applications. Results of this study indicated that both durability and impact resistance of the deposits, sprayed with these new powders, were significantly improved, and their wear resistance was equal or superior to conventional WC cermet coatings. This was achieved by optimizing both the spray powder chemistry, and also the HVOF spray conditions (for the new powders) to cater to the improved quality requirements for wear, corrosion, and impact resistance. It is expected that the high impact resistance of the new generation powders will open up new markets for the use of HVOF coatings for construction machinery parts such as excavating tools and shovels. For instance, it was found that excavating tools with the coating demonstrated approximately 16 times longer life than conventional tools without the coating. The mechanism for improving the impact resistance of the coating was also investigated in this study.