Elevated-temperature tribological behavior of Ti-B-C-N coatings deposited by reactive magnetron sputtering

Quaternary Ti-B-C-N coatings with various carbon contents were deposited on high-speed steel (HSS) substrates by reactive magnetron sputtering (RMS) system. The elevated-temperature tribological behavior of Ti-B-C-N coatings was explored using pin-on-disk tribometer, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The present results show that the steady-state friction coefficient value and the instantaneous friction coefficient fluctuation range of Ti-B-C-N coatings decrease as carbon content increases at 100 and 300 A degrees C, while the steady-state friction coefficient value of all Ti-B-C-N coatings becomes higher than 0.4 at 500 A degrees C. As ambient temperature increases, the running-in periods of all Ti-B-C-N coatings become shorter. Wear damage to Ti-B-C-N coatings during sliding at elevated temperature is mainly caused by adhesive wear, and adhesive-wear damage to Ti-B-C-N coatings increases as ambient temperature increases; however, higher carbon content is beneficial for decreasing the adhesive-wear damage to Ti-B-C-N coatings during sliding at elevated temperature.