Use of nanoscaled multilayer and compound films to realize a soft lubrication phase within a hard, wear-resistant matrix

An ideal solid lubricant would have a very low friction coefficient coupled with high wear resistance. It has thus been imagined to include clusters of a lubricating material dispersed within a hard matrix. Such a composite coating might provide both a wear-resistant surface and some solid lubrication, with new pockets of lubricant being exposed as the film wears down. The goal is to extend the historical use of MoS2 in spacecraft, to common industrial environments such as in dry or reduced-lubricant machining, and in machinery. Anti-adhesive properties can also be important, for example in extruding and molding. Modern thin film deposition technologies present possibilities to produce such film structures, both from process and control perspectives. It has been demonstrated that MoS2 can be added to hard, wear-resistant ceramic films such as TiN or CrN. An opposite approach could be to increase the hardness and perhaps wear resistance of a solid lubricant. Adding elements or compounds to the solid lubricant MoS2 produced increases in sliding lifetime, and in at least some cases, hardness. Tribological testing in humid atmospheres indicated that low friction coefficients combined with wear resistance can be realized. (C) 2000 Published by Elsevier Science S.A. All rights reserved.