Enhanced tribological properties of Y/MoS2 composite coatings prepared by chemical vapor deposition

Chemical vapor deposition (CVD) is an efficient approach to prepare coatings on complex cutting tools. However, MoS 2 with self-lubrication ability and excellent tribological properties fabricated by CVD have been rarely reported in literature. The aim of this study was to deposit pure MoS 2 coatings and yttrium (Y) doped MoS 2 (Y/MoS 2 ) composite coatings on cemented carbide blades coated with titanium nitride by CVD. The structural and mechanical properties of the coatings were examined by scanning electron microscopy (SEM) and nanoindentation , respectively. The results demonstrated that the microstructure of Y/MoS 2 composite coatings was denser than that of the pure MoS 2 coating. The hardness and the adhesional properties were significantly enhanced for the Y/MoS 2 composite coatings. The tribological performance of the as-deposited coatings were investigated under atmospheric environment. Y/MoS 2 compostite coatings demonstrated an enhanced tribological performance with a stable and low coefficient of friction (COF) over the entire sliding time. In contrast, the COF of pure MoS 2 coating dramatically increased to value above 0.3 after a sliding time of only 30 min. Additionally, the Y/MoS 2 composite coatings showed a decreased wear rate (8.36 ± 0.29 × 10 −7 mm 3 /Nm) compared to the pure MoS 2 coatings (3.41 ± 0.48 × 10 −5 mm 3 /Nm) thus reflecting an improvement by two order of magnitude.