SELF-LUBRICATING PLASMA-SPRAYED COMPOSITES FOR SLIDING-CONTACT BEARINGS TO 900° C

摘要

Plasma-sprayed composites which have good oxidation-resistance and self-lubricating character¬istics to 900℃ were developed. The composites are a Nichrome matrix containing dispersed glass for oxidation protection and calcium fluoride for lubrication. They are applied to bearing surfaces in layers about 0. 050 cm thick by plasma-spraying;the layers are then machined to a thickness of 0. 025 cm. Oscillating bearing tests were performed in air to 900° C at unit radial loads up to 3. 5x107 N/m2 (5000 psi) and a thrust load of 1960 N (440 lb). Bearings with a com-posite liner in the bore were in good condition after over 50 000 oscillating cycles accumulated during repeated bearing temperature cycles between 25° and 900℃.