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-BC-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 TiB-C-N coatings decrease as carbon content increases at100 and 300 ℃,while the steady-state friction coefficient value of all Ti-B-C-N coatings becomes higher than 0.4 at500 ℃.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.