H. Heshmat, ROLLING AND SLIDING CHARACTERISTICS OF POWDER-LUBRICATED CERAMICS AT HIGH-TEMPERATURE AND SPEED, Lubrication engineering, 49(10), 1993, pp. 791-797
As part of a high-temperature, dry-lubricated bearing technology and l
ubricant system development program, a high-speed, high-temperature di
sk-on-disk tribometer was utilized and a matrix of traction data cover
ing a range of load, speed and temperature were obtained. The influenc
e of dry powder lubricants (TiO2 powders with different particulate si
zes, ZnMoO2S2 and NiO) on the traction coefficients between two tribo-
ceramic materials (Si3N4 vs. Si3N4) was investigated. The most importa
nt results of this investigation were characteristic curves for the tr
action 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 decrease
d moderately with slide-to-roll ratio and load. The powder data, unlik
e the unlubricated condition (dry), showed a slight sensitivity to tem
perature.