Influence of Detonation Spray Parameters on the Formation of Mechanical and Tribological Properties of Gradient Coatings based on Alumina

Abstract

Using the detonation method, the shaft was filled with a gas mixture of C₂H₂/O₂ from 53 to 68 % and an alumina-based gradient coating was obtained on the surface of the substrate. The microstructure of the coatings was studied by scanning electron microscopic analysis. By increasing the proportion of α-Al₂O₃ phase towards the surface layer of the coating by 10–15 %, a coating layer with increased strength and wear resistance was received. By X-ray structural study, changes in the α-Al₂O₃ lattice were studied by reducing the amount of gas filling in the barrel and the firing time from 1 s to 0.25 s. By reducing the amount of gas in the shaft from 68 to 53 % and the firing time from 1 s to 0.25 s, a compatible gradient coating with improved mechanical properties was obtained, the maximum value of microhardness of the gradient coating was 23.73 GPa. The tribological properties of the coatings were studied and showed that the value of the coefficient of friction of the gradient coating is about 50 % lower than that of other coatings, i.e. wearresistant.