Friction and wear behaviour of unfilled engineering thermoplastics

Friction, wear and fatigue are three most commonly encountered industrial problems leading to the replacement of components and assemblies in engineering. In this investigation we studied and explored the influence of test speed and load values on the friction and wear behaviour of polyamide 6 (PA 6), polyoxymethylene (POM) and ultra-high molecular weight polyethylene (UHMWPE) engineering polymers. Friction and wear tests of those polymers against ostenitic stainless steel were carried out at dry condition on a pin-on-disc arrangement. These tests were carried out at room temperature, under 20-, 30- and 40-N loads and at 0.88 and 1.76 m/s sliding speeds. The specific wear rates were obtained from mass loss. The results showed that the coefficient of friction for polyamide 6, POM and UHMWPE slightly increases with the increase in load. At 0.88 m/s sliding speed, the specific wear rate for polyamide 6 and UHMWPE were in the order of 10−6 mm3/Nm while the wear rate value for POM was in the order of 10−5 mm3/Nm. Moreover, for the range of load and speeds of this investigation, the specific wear rate showed very little sensitivity to the applied load and large sensitivity to test speed.