EROSIVE WEAR OF CVD CERAMIC COATINGS EXPOSED TO PARTICULATE FLOW

Chemical vapor deposition (CVD) was used to apply titanium carbide, titanium nitride and alumina multilayers to a cemented tungsten carbide substrate. The erosion behavior of these coatings was investigated experimentally by exposing them to particle-laden flow in a specially designed wind tunnel. The eroded surface was then examined by scanning electron microscopy. The erosion results show the effects of velocity, temperature, impingement angle and mass of the impacting particles on the erosion rate. The results indicate that the erosion rate is proportional to the particle velocity to the power n, where the velocity exponent, n, varies from 2.61 to 2.82. The variation of temperature and the particle impingement angle did not substantially affect the coating erosion rates. This study indicates that the tested ceramic coatings provide excellent resistance in the particulate flow environment.