Surface Interactions and Lubrication Response of Silicon Nitride Bearing Elements.

Abstract : The report summarizes results of a fundamental investigation of the suitability of silicon nitride as a rolling bearing material with emphasis on its interactive behavior with lubricating fluids. The need for a light-weight bearing material in critical high-speed turbine applications is discussed and the potential benefits of silicon nitride in particular are reviewed. The wettability characteristics of six lubricants on a silicon nitride surface were measured to determine which lubricants are apt to be successful with silicon nitride bearing components in permitting the replenishment of lubricant onto the rolled-over tracks which is vital for the maintenance of an elastohydrodynamic (EHD) film and the consequent prevention of surface initiated fatigue. (Modified author abstract)