Thermal evaluation of TiN/CNx multilayer films

This work examines the thermal behavior and failure mechanisms of TiN/CNx multilayer coatings deposited by DC magnetron sputtering. The samples were examined by transmission electron microscopy before thermal analysis. During thermal analysis, the samples were heated up to 1070 K at a constant rate of 10 K min−1 in a N2 atmosphere and their thermal stability was evaluated by thermo gravimetric (TGA) and differential thermal analyses (DTA). These analyses indicate that the multilayer coating is thermally stable up to 950 K, followed by stress relaxation when the temperature exceeds 950 K. After this thermal treatment, coating surfaces were observed by scanning electron microscopy. Buckling and fractured surface were seen for multilayers deposited with and without substrate bias voltage applied during growth process, although samples deposited with substrate bias are more resistant to crack formation and propagation.