A study on the friction and wear behavior of PTFE filled with alumina nanoparticles

A solid lubricant composite material was made by compression molding PTFE and 40 nm alumina particles. Prior to compression molding the constituent powders were blended using a jet milling apparatus. Composites from 0 to 20 wt.% were prepared. These composites were tested against a polished stainless steel counterface on a reciprocating tribometer. The experimental conditions were a contact pressure of 6.4 MPa, a stroke length of 50 mm, and a sliding speed of 50 mm/s. The friction coefficient of the composite increased over unfilled samples from roughly μ=0.15 to μ=0.2. At filler concentrations of 20 wt.%, the wear resistance improved 600×. The wear resistance of this composite increased monotonically with increasing filler concentration and no optimum filler fraction was found.