What sets SurfTec’s coating apart from other solid lubricant coatings used in bearings, is the absence of a resin binder intermixed with the lubricant coating. Although the use of resin binders reduces wear, it also increases the COF of solid lubricant coatings. SurfTec’s coating has been engineered to be self-lubricating thanks to the formation and removal of a transfer film at the interface between the coating and counterface.
Below are SEM micrographs of SurfTec’s coating compared with pure PTFE coating. (a) pure PTFE coating, (b) PTFE delamination from substrate after initial wear, (c) abraded substrate after prolonged wear, (d) SurfTec’s coating, (e) compressed SurfTec coating after initial wear, (f) SurfTec coating after prolonged wear.
SurfTec’s PTFE top-coat can be further enhanced by incorporating nanoparticle fillers into the coating. The addition of nanoparticle filler increases the the load carrying capacity of the film and reduces the wear rate of the film. AFM topolographical images have been captured which depict the nanoparticles in a PTFE matrix.