Coefficient of Friction of PTFE-Impregnated Porous Bronze Versus Temperature.

摘要

DU (registered trademark of the Glacier Medal Company, Ltd.) is a composite material consisting of sintered bronze, impregnated primarily with polytetrafluorethylene (PTFE), mounted on a steel backing. It is used as a dry lubricant in bushings and for such components as hinges both on the ground and in space. The coefficient of friction in vacuum of DU on hard anodized aluminum coated with the DU was shown to double as the temperature was lowered from 60 to -20C. The expression mu = 1.33 exp(-0.01092T) was derived to describe this behavior. The derivation was made with the expression mu = s/p as a basis, where s = shear strength of PTFE, and p = hardness of bronze. The resulting equation or mu fits the data excellently, thereby demonstrating the validity of the adhesion theory of friction for this material. (Author)