In Situ Studies of TiC1−x N x Hard Coating Tribology
TiC1−x N x hard coatings present time-dependent tribological behavior with an initial running-in period (500–2000 cycles) marked by an elevated friction coefficient, followed by >10000 cycles with low-friction and wear at room temperature (RT) in ambient air. The mechanisms behind this behavior are not completely understood. Tribological tests performed at RT and at different relative humidity (RH) levels revealed that a minimum value between 15 and 25% RH is needed to trigger the low-friction regime at a sliding speed of 100 mm s−1. By in situ observations of transfer film growth, it could be observed that third body material is formed during this running-in period by plowing of the coating and shearing of the removed material. The appearance and thickening of the transfer film marks the beginning of the steady-state low-friction regime where the velocity is accommodated by interfacial sliding. At this stage in the tribological test, the recorded Raman spectra indicated the presence of C–H bonds in the wear track. Use of in situ analytical tools during wear tests provided insights with respect to tribological phenomena that were not available by conventional, post-mortem analysis methods.
Copyright © 2010, Springer
Rebelo de Figueiredo, Marisa; Muratore, Christopher; Franz, Robert; Chromik, Richard R.; Wahl, Kathryn J.; Voevodin, Andrey A.; O'Sullivan, Michel; Lechthaler, Markus; and Mitterer, Christian, "In Situ Studies of TiC1−x N x Hard Coating Tribology" (2010). Chemical and Materials Engineering Faculty Publications. 137.