Temperature dependent tribooxidation of Ti–B–N coatings studied by Raman spectroscopy

In this work, tribological wear tracks formed on moderate temperature chemical vapor deposited (MTCVD) TiB1.66N0.34 coatings were characterized by Raman spectroscopy and compared to those obtained on TiN. Therefore, ball-on-disk sliding tests against Al2O3 as well as 100Cr6 bearing steel were performed at room and elevated temperatures (25–700 °C). Raman microspectroscopy was found to be essential to identify different oxide and borate phases on the wear tracks, which originate from tribochemical reactions and tribooxidation. Furthermore, it was shown that the temperature dependence of tribological reactions at the interface can successfully be studied by combining exceptional short sliding distances with post-annealing experiments at different temperatures and durations. A good correlation between the detected compounds on the wear tracks and the observed friction coefficient was achieved.