The experimental evaluation and application of high temperature solid lubricants

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6614011

Dellacorte, C

A research program meant to develop an understanding of high temperature solid lubrication and experimental techniques through the development of a composite lubricant coating system was described. The knowledge gained through this research was then applied to a specific engineering challenge, the tribology of a sliding seal for hypersonic flight vehicles. The solid lubricant coating is a chromium carbide based composite combined with silver, which acts as a low temperature lubricant, and barium fluoride/calcium fluoride eutectic, which acts as a high temperature lubricant. This composite coating provides good wear resistance and low friction for sliding contacts from room temperature to over 900 C in reducing or oxidative environments. The specific research on this coating included a composition screening using a foil gas bearing test rig and the use of thin silver films to reduce initial wear using a pin-on-disk test rig. The chemical stability of the materials used was also addressed. This research indicated that soft metallic films and materials which become soft at elevated temperatures are potentially good lubricants. The general results from the experiments with the model solid libricant coating were then applied to a sliding seal design concept. This seal design requires that a braided ceramic fabric slide against a variety of metal counterface materials at temperatures from 25 to 850 C in an oxidative environment. A pin-on-disk tribometer was used to evaluate the tribological properties of these materials and to develop lubrication techniques. The results indicate that these materials must be lubricated to prevent wear and reduce friction. Thin films of silver, gold and calcium fluoride provided lubrication to the sliding materials. The data obtained and the lubrication techniques developed provide important information to designers of sliding seals.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA)
• OSTI ID: 6614011
• Resource Relation: Other Information: Ph.D. Thesis
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM FLUORIDES
TRIBOLOGY
CALCIUM FLUORIDES
CHROMIUM CARBIDES
BEARINGS
CERAMICS
EUTECTICS
GOLD
SILVER
SLIDING FRICTION
SOLID LUBRICANTS
THIN FILMS
WEAR
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CARBIDES
CARBON COMPOUNDS
CHROMIUM COMPOUNDS
ELEMENTS
FILMS
FLUORIDES
FLUORINE COMPOUNDS
FRICTION
HALIDES
HALOGEN COMPOUNDS
LUBRICANTS
METALS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
360603* - Materials- Properties