Surface properties of W-implanted TiN coatings post-treated by low temperature ion sulfurization

Abstract

TiN coatings were implanted with W ions by metal vapor vacuum arc (MEVVA) source at dose of 9×1017ions/cm2, and then they were post-treated by low temperature ion sulfurization (LTIS) at 160°C. The W-implanted TiN samples were characterized before and after post-treatment of LTIS, using Scanning Electron Microscopy (SEM), Scanning Auger Microprobe (SAM), X-ray diffraction (XRD), and Nano Indenter System. Friction and wear properties were evaluated using a ball-on-disc tribometer under dry sliding in air. After post-treatment of LTIS, XRD results showed no diffraction peaks of tungsten sulfides on surfaces of W-implanted TiN coatings; W-implanted TiN coatings were sputtered by the sulfur plasma with about 36% reducing of W depth. Further, the nano-hardness decreased mainly due to the amount decreasing of Ti2N and the formation of more metal oxides on surfaces of W-implanted TiN coatings after LTIS. As a result, LTIS treatment could not well improve tribological properties of W-implanted TiN coatings.