Structural sensitivity of MoS2-based films in solid space lubrication

The Ti/MoS2 films with nano-composite and nano-multilayer structures are synthesised as well as the pristine MoS2 film by unbalanced magnetron sputtering. The effects of film structure on the solid lubrication performance in vacuum have been investigated. The microstructural analysis by scanning electron microscope and transmission electron microscope displays that the addition of Ti in MoS2 films with both nanostructures hinders the growth of columnar grains, leading to the improved compactness of films and mechanical properties. Through the analysis, it is found that the metallic titanium in the form of nanocrystals can transform into fine and uniform wear debris which benefits the preserve of transfer film, while the large and non-uniform debris resulted from the layer form can lead to localised severe damage and unstable friction.