Wear and friction of nylon-glass fibre composites in non-conformal contact under combined rolling and sliding

Results from twin disc tests of glass fibre reinforced Nylon 66 running against itself are presented. It is shown that the low friction and wear rates often found under these conditions are due to the formation of a thin interfacial layer of nylon over the composite. After substantial wear the subsurface becomes saturated with glass fibre debris, the interfacial layer is abraded and the wear rate increases substantially. The persistence of the surface layer appears to be related to the crystallinity of the nylon matrix with low crystallinity materials running for hundreds of hours with virtually no wear while high crystallinity materials fail rapidly.