Rolling and Sliding Characteristics of Powder-Lubricated Ceramics at High Temperature and Speed

Heshmat, H. “Rolling and Sliding Characteristics of Powder-Lubricated Ceramics at High Temperature and Speed,” 47th Annual Meeting of the STLE, Philadelphia, PA, May 1992, (1993) Lubrication Engineering, Volume 49 (10), pp. 791-797.

As part of a high-temperature, dry-lubricated bearing technology and lubricant system development program, a high-speed, high-temperature disk-on-disk tribometer was utilized and a matrix of traction data covering a range of load, speed and temperature were obtained.  the influence of dry powder lubricants (TiO2 powders with different particulate sizes, ZnMoO2S2 and NiO) on the traction coefficients between two tribo-ceramic materials (Si3N4 vs. Si3N4) was investigated.  The most important results of this investigation were characteristic curves for the traction coefficient vs. the slide/roll ratio with dry powders which are reminiscent of fluids, and the observation that dry powder lubricants lowered traction coefficients and wear.  measured tractions were found to be a strong function of powder lubricant type, and values decreased moderately with slide-to-roll ratio and load.  the powder data, unlike the unlubricated condition (dry), showed a slight sensitivity to temperature.