Effect of PAO-4 and MoDTC + ZnDTP oil additive lubricants on the tribological performance of novel tetrahedral amorphous carbon (ta-C) coatings

This study was carried out to assess the effect of PAO-4 and mineral oil mixed with MoDTC and ZnDTP on the tribological performance of novel tetrahedral-amorphous-carbon (ta-C) coatings namely P:ta-C, and M:ta-C, were analysed using the Pin-on-Disk Tribo-tester with a fixed normal load, temperature, sliding distance and speed of 20 N, 80 °C, 250 m and 0.068 ms−1 for 60 min, respectively. The C:ta-C, P:ta-C, and M:ta-C showed excellent wear resistance when lubricated with MoDTC + ZnDTP. The formation of weak Zn-derived tribofilm on the P:ta-C coating contributed to the strong wear resistance and reduced friction coefficient. Moreover, the passive transfer of ferrous compounds from the SUJ2 disk induced the development of weak Zn-derived tribofilm on the P:ta-C and M:ta-C.