ABSTRACT
Parallel to the effect of the length-to-width ratio in hydrodynamic bearings, the orientation of a rectangular slider made a difference in powder layer performance. While the foregoing generic tests and the conceptualization of powder lubrication as a quasi-hydrodynamic process have been more or less established, this chapter goes beyond these qualitative efforts to generate a quantitative base for the application of this new technology. The experimental results described data on the morphological, thermodynamic, and rheological characteristics of powder layers, as well as their special tribological features. The chapter considers two important tribological facets of powders. One is that its shear and damping properties, as in addition to its role as lubricants, a powder layer can serve as an effective medium in attenuating vibrations in dampers, turbine blades, aircraft control surfaces, and other structures subject to high-frequency fatigue. The other outstanding issue is to secure a powder supply to the interface on a sustained basis.
