Structure and properties of DLC–MoS2 thin films synthesized by BTIBD method

Abstract

Diamond-like carbon (DLC)–MoS2 composite thin films were synthesized using a biased target ion beam deposition (BTIBD) technique in which MoS2 was produced by sputtering a MoS2 target using Ar ion beams while DLC was deposited by ion beam deposition with CH4 gas as carbon source. The structure and properties of the synthesized films were characterized by X-ray diffraction, X-ray absorption near edge structure (XANES), Raman spectroscopy, nanoindentation, ball-on-disk testing, and corrosion testing. The effect of MoS2 target bias voltage, ranging from −200 to −800V, on the structure and properties of the DLC–MoS2 films was further investigated. The results showed that the hardness decreases from 9.1GPa to 7GPa, the Young׳s modulus decreases from 100GPa to 78GPa, the coefficient of friction (COF) increases from 0.02 to 0.17, and the specific wear rate coefficient (k) increases from 5×10−7 to 5×10−6mm3N−1m−1, with increasing the biasing voltage from 200V to 800V. Also, the corrosion resistance of the DLC–MoS2 films decreased with the raise of biasing voltage. Comparing with the pure DLC and pure MoS2 films, the DLC–MoS2 films deposited at low biasing voltages showed better tribological properties including lower COF and k in ambient air environment.