Lubricant coatings

Abstract

Provided are methods for fabricating solid lubricant coatings capable of operating over a temperature range of at least 0.degree. to 600.degree. C. One embodiment comprises simultaneously applying a first solid lubricant and a second solid lubricant to a bearing surface, wherein the first solid lubricant has a normal operating temperature range of about -169.degree. to +350.degree. C. and the second solid lubricant has a normal operating temperature range of about 350.degree. to 700.degree. C. A second embodiment comprises applying multiple alternating layers of a first solid lubricant and a second solid lubricant to a bearing surface. A third embodiment comprises applying multiple alternating layers of (1) a first solid lubricant overlaid with a diffusion barrier and (2) a second solid lubricant overlaid with a diffusion barrier to a bearing surface. A fourth embodiment comprises applying at least one matrix layer consisting essentially of a first solid lubricant and a second solid lubricant dispersed in a diffusion barrier matrix to a bearing surface. The first and second solid lubricants in these embodiments are as described above. The diffusion barrier is a metal carbide, metal nitride or the like. The lubricant films prepared according to the invention are able to adapt to environmental changes such as temperature, atmosphere, pressure, radiation levels and the like. The adaptive nature of these lubricant films occurs through changes in crystal structure and reaction between the first and second solid lubricants, both with each other and with the atmosphere.