Preparation and friction characteristics of self-lubricating TiN-MoS2 composite coatings

Composite coatings consisting of discrete phases of TiN and MoS2 were codeposited on graphite and Ti-6Al-4V substrates from Ti((CH3)2N)4/NH3/MoF6/H2S gas mixtures. Chemical composition and microstructure of the coatings were characterized by Auger electron spectroscopy, X-ray diffraction, and transmission electron microscopy. Friction coefficients at room temperature in air were typically in the range of 0.07 to 0.3. The friction coefficients remained comparable at 573 K, but increased to 0.7 to 1.0 at 673 K. A friction coefficient value of ∼0.3 was, however, obtained from a composite coating tested at 973 K.