Sputter-deposited lubricant thin films for high-temperature applications

The major objective of this research program is to investigate and produce lubricant multilayer coatings deposited by sputtering to provide friction coefficients as bow as 0.3 in air at temperatures varying from room temperature to 800 degrees C under tribological test conditions appropriate to specific lubrication applications. The friction properties (friction coefficients and wear rates) of sputter-deposited silver, calcium fluoride and Ag/CaFx multilayer structures determined under various tribological conditions are reported. The tribological properties of sputter-deposited CaFx/Cr3C2 thin bilayer structures at 500 degrees C and 700 degrees C in air are compared to those of thick coatings of plasma-sprayed composite material (PS-212-type) similar to coatings developed by NASA.