The Effect of Compositional Tailoring on the Thermal Expansion and Tribological Properties of PS300: A Solid Lubricant Composite Coating

Abstract

This paper describes a research program in which the goal is to alter the thermal expansion coefficient of a composite solid lubricant coating PS300, by compositional tailoring. PS300 is a plasma-sprayed coating consisting of chrome oxide, silver and barium fluoride/calcium fluoride eutectic in NiCr binder. By adjusting the composition, the thermal expansion coefficient can be altered, and hence chosen, to more closely match a selected substrate preventing coating spallation at extreme temperatures. Thermal expansion coefficients (CTEs) for a variety of compositions were measured from 25° to 800°C using a commercial dilatometer. The CTEs ranged from 7.0 to 13 × 10⁻⁶/°C depending on the binder content. Subsequent tribological testing of a modified composition indicated that friction and wear properties were generally comparable, and for some operating conditions superior, to the original composition.

Presented at the 52nd Annual Meeting in Kansas City, Missouri May 18–22, 1997

KEY WORDS:

• Solid Lubricant
• Surface Films/Coatings
• Adverse Environments Tribology

Notes

Presented at the 52nd Annual Meeting in Kansas City, Missouri May 18–22, 1997