Correlating high temperature mechanical and tribological properties of CrAlN and CrAlSiN hard coatings

Abstract

CrAlN and CrAlSiN hard coatings deposited by magnetron sputtering were analyzed for their high temperature mechanical and tribological properties. High temperature nanoindentation measurements on both coatings were performed from room temperature up to 700 °C in steps of 100 °C where a reduction in hardness H and elastic modulus E* from their initial values was noticed. In addition, high temperature tribological tests were conducted in inert atmosphere in the same temperature range to obtain information about the coefficient of friction and the wear coefficient. In order to link the tribological behavior to the obtained mechanical properties, the H/E* ratio was calculated and compared to the high temperature wear from the current and other studies with similar coatings. The evolution of the mechanical and tribological properties at high temperature is discussed based on the current knowledge available in literature.