Experimental investigations of Al₂O₃- and ZrO₂-based coatings deposited by detonation spraying

This paper presents the results of experimental investigations of the physical and mechanical properties, structure and surface morphology of Al₂O₃- and ZrO₂-based coatings deposited by detonation spraying. The coatings were sprayed onto titanium-alloyed steel 12Ch18N10T (GOST 4986-79). The thickness of the coatings ranged from 250 to 1100 μm. After the deposition of the coatings the mechanical properties of the steel's surface layer significantly improved. Its microhardness increased threefold, reaching the maximum value of over 11 GPa. Also the tribological properties of the material detonation sprayed onto the steel were tested. A significant decrease in the kinetic friction coefficient was observed. For the steel with the ZrO₂ coating the friction coefficient decreased by nearly half, reaching the value of 0.330. An increase in abrasive wear resistance was noted. Moreover, the results of electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction examinations evaluating the structural properties and surface morphology of the coatings are presented. (paper)