Microscale abrasive wear of polymeric materials

Polymeric materials are now commonly employed as components in mechanical devices, and as such are subject to wear. Abrasive wear of polymer components may occur either by sliding against a rough counterface or by abrasion by hard particles. Whilst previous work has considered the three body abrasion of polymers using large abrasives common in the ASTM G65 test, this work presents results concerning three-body abrasion of polymers with a fine (2–5 μm) SiC abrasive. The test employs a rotating sphere as the counterface against which the test specimen is loaded with abrasive slurry being entrained. It is demonstrated that the test provides valid results for all polymer types only at low loads which aid slurry entrainment. Test parameters are identified where the test results yield little concerning true material behaviour, reflecting instead something of the test characteristics. Under conditions which are deemed to yield results reflecting the true wear rates of the polymers, the expected spherical cap geometry of the wear scar is established very early in the test sequence. A range of polymers has been examined. The samples are well discriminated by the test, and a reasonable correlation with both the Martens hardness and the Ratner–Lancaster factor (1/σbεb) is found.