Structural and tribological characterization of tungsten nitride coatings at elevated temperature

The structure, hardness, friction and wear of tungsten nitride coatings with nitrogen content in the range 30-58 at.% prepared by dc reactive magnetron sputtering were investigated. The tribological tests were performed on a pin-on-disc tribometer in terrestrial atmosphere with Al2O3 balls as sliding partner. The coating wear rate was negligible up to 200 °C exhibiting a decreasing tendency; however, the wear dramatically increased at higher temperatures. The coating peeled off after the test at 600 °C, which is connected with the oxidation of the coating.