COMPARATIVE STUDY OF FRETTING BEHAVIOURS OF HVOF-SPRAYED COATINGS AT ROOM AND HIGH TEMPERATURE

This paper provides a study of sliding wear behavior of Cr3C2-CoNiCrAlY thermally sprayed coating at room and high temperature -600 degrees C. Wear testing was realized by linearly reciprocating Ball-on-Flat sliding wear test according to ASTM G133-05, so called fretting test using the tribometer CETR-UMT3. The evaluation addresses specifically wear resistance, friction characteristic and sliding wear mechanisms. The coatings were examined by SEM imaging. The Cr3C2-CoNiCrAlY HVOF coating proved its potential as a coating for high temperature sliding or fretting application. Measured COF decreased together with increasing temperature. On the other hand, the wear resistance decreased at high temperature in the vicinity of oxide originated in the wear scar.