Study of titanium nitride deposition by supersonic plasma spraying

In this study, titanium nitride (TiN) deposition by reactive spraying was carried out under a low-pressure environment using a DC arc plasma jet generator with a supersonic expansion nozzle. Titanium powders were injected using a hollow cathode with argon gas, and nitrogen or nitrogen and hydrogen mixture was used as the plasma gas. Microstructure and properties of the coatings were examined using scanning electron microscope and X-ray diffraction. A dense TiN coating with a Vickers hardness of 2000 Hv was formed at a substrate temperature of 700 °C with a low input power of 5.3 kW. The results showed that the supersonic plasma jet in thermodynamic and chemical nonequilibrium state exhibits high potentials for reactive spraying.