THE EFFECT OF CONTROLLED COUNTERFACE TOPOGRAPHY ON POLYMER TRANSFER AND WEAR

Counterface topography affects the formation, retention, and replenish ment of transfer films. These films often dominate the tribological ch aracteristics of materials such as polymers, solid lubricants, and thi n-films. To investigate the effect of mechanical surface irregularitie s on polymer transfer and wear, a surface scribing device was built, c apable of imparting controlled topographical features to disk specimen s for vertical pin-on-disk testing. In this study, hardened steel disk s were scribed for testing with PAI (polyamide-imide) and HDPE (high d ensity polyethylene) polymer pins. For both materials, the results ind icated that wear rate increases with increased surface roughness, whil e there is no significant effect on the wear rate by increased roughne ss spacing. In addition, a stable and well adhered transfer ''film'' f ormed at lower surface roughness while loosely adhered unstable transf er ''layers'' formed at higher surface roughness.