Relationship between tribological properties and oxidation behavior of Ti0.34Al0.66N coatings at elevated temperature up to 900 °C

In this study, Ti0.34Al0.66N coatings were fabricated by arc ion plating (AIP) process on ceramic carbide substrates. The tribological tests were carried out by using a ball-on-disc tribometer with different temperatures from 25 °C to 900 °C in air. After high-temperature testing, the microstructure, chemical composition, oxidation behavior and mechanical properties were investigated using X-ray diffraction, Auger electron spectroscopy, X-ray photo-electron spectroscopy, scanning electron microscopy and nanoindentation tests. Phase separation and crystallization of oxide layer occurred at 900 °C. The decrease of surface hardness and significant improvements on wear resistance were obtained at high temperatures, which were connected to the oxidation behavior of Ti0.34Al0.66N coatings. The results showed that the formation of oxide layer determined the contacting state between the slider and coatings at elevated temperatures, and was responsible for the changes in wear mechanisms.