THE QUASI-HYDRODYNAMIC MECHANISM OF POWER LUBRICATION .1. LUBRICANT FLOW VISUALIZATION

The object of the present paper is to present a systematic development of the concept of powder lubrication as a viable tribological process. The quasi-hydrodynamic nature of powder lubrication is deduced from the observation that a number of basic features of powder flow in narrow interfaces exhibit the characteristic behavior of fluid film lubrication. In addition to corroborating the basic mechanism of powder lubrication, the conceptual and experimental work performed here provides an evaluation of the parameters and geometries relevant to this particular tribological process. The present part of the investigation presents visual documentation of the fluid-like flow of a powder lubricant in bearing and seal-like clearances, thus establishing the basis and departure point for the experimental and theoretical work to be reported in future work.