Microstructure and high-temperature tribological properties of Ti/Si co-doped diamond-like carbon films fabricated by twin-targets reactive HiPIMS

Abstract

In order to enhance high-temperature tribological properties of the diamond-like carbon (DLC) films, Ti/Si co-doped DLC films were synthesized by twin-targets reactive high power impulse magnetron sputtering and effects of doped elements on mechanical performances were investigated. The results showed that a mid-doped DLC film with a Ti content of 13.8 at.% and a Si content of 12.6 at.% obtained the best high temperature tribological performance and its wear resistance was significantly less affected. The friction coefficient of the Ti/Si co-doped DLC film at 450 °C dropped to as low as 0.08. In addition, compared with the mono Ti-doped DLC film, its wear rate at 450 °C decreased from 5.24 × 10−4 to 1.40 × 10−5 mm3·N−1·m−1. Raman spectra revealed that Si could hinder the sp3-C to sp2-C transition at elevated temperatures, which impeded adhesive wear in the high temperature tribological process.