Improving the Efficiency of Air Plasma Spraying of Titanium Nitride Powder

Abstract

The operation modes of a plasmatron for powder coating spraying have been studied. The plasmatron has a node of annular input and a gasdynamic focusing of the powder, and the outlet holes of the nozzle-anode are made in the form of rectangular narrowing-expanding channels (No.34334 RK: IPC H05H 1/42). The dynamics and trajectories of the powder particles in the plasmatron were investigated. The paper analyzes the influence of plasmatron arc current and working gas flow rate on the structure and properties of the obtained coatings. It is established that the phase composition of the sprayed coatings and the initial powder is the same: the main phase is the compound TiN, in addition, the structure contains the phase TiO2. The results of tribological tests of the coatings under dry friction conditions according to the ball-on-disk scheme are presented. Within the framework of this study, it can be said, from the point of view of obtaining denser coatings with high performance characteristics, that the optimal modes of plasma spraying of TiN powder are a current of 250 A and the working gas flow rate of argon 34 L/min.