Advances in solid lubrication with MoS 2 multilayered coatings

The general classification of solid lubricant types is reviewed, along with the reasons for choosing and methods of depositing solid lubricants, in particular MoS 2 . The best‐performing and most flexible technique for making MoS 2 films is by physical vapour deposition (PVD), and the variants of that technology are considered. The intrinsically‐lubricating, lamellar structure of pure MoS 2 is described, along with a brief summary of the wear and failure modes. Present applications for lubrication by MoS 2 in spacecraft and dry machining are described. Anti‐adhesion uses in extruding and moulding are also mentioned. The current modification of MoS 2 films is by addition of dopants (co‐sputtering), by multilayering as a series of films each fulfilling a specific task, or by stacking repeating nanometre‐scale films. Composite films of MoS 2 islands in a hard film matrix are also being developed.