Effect of High Velocity Oxygen Fuel Sprayed WC-10Co4Cr Coating on Resistance to Wear and Corrostion of TC11 Titanium Alloy

The cermet coating was prepared on the surface of TC11 titanium alloy, a common material of drilling instrument parts, by high velocity oxygen fuel spraying (HVOF). The impact toughness of titanium alloy before and after spraying was measured by impact tester. The wear resistance of the coating was measured by abrasive wear tester. The corrosion resistance of the coating was analyzed by electrochemical test. The results show that the HVOF process had little effect on the microstructure and properties of TC11 titanium alloy. Compared with the unsprayed titanium alloy, the microstructure and microhardness at the interface of the coating did not change significantly, and the impact toughness was slightly improved. The HVOF process was stable and reliable. The coating had a lamellar structure and high density. The porosity of the coating was 2.55%, and the hardness reached 1 400 HV. The coating was mainly composed of WC and W₂C phases, which were well combined with the substrate and were mechanically bonded. The cermet coating could significantly improve the wear resistance and corrosion resistance of titanium alloy. The wear amount of titanium alloy after spraying coating was 1.56% of that of unsprayed titanium alloy. The wear mechanism of titanium alloy with spraying coating was abrasive wear, and the wear mechanism of titanium alloy without spraying coating was abrasive wear + adhesive wear.