Friction and wear characteristics of WC-Co cemented carbides in dry reciprocating sliding contact

Friction and wear properties of WC-Co cemented carbides with Co concentrations ranging from 6 up to 12 wt% and WC grain sizes in the sub-micrometer scale have been examined in reciprocating sliding wear experiments using a high-frequency TE77 pin-on-plate system. The aim of the work was to investigate the influence of test parameters such as normal contact force, oscillating velocity and sliding distance on the tribological characteristics. The tests were carried out under unlubricated conditions. The generated wear was quantified volumetrically by means of surface topography scanning measurements. The changes in test parameters gave a variation in wear of more than one order of magnitude. A marked increase in wear was seen as the load increased, whereas the friction coefficient displayed an opposite trend. Raising the oscillating speed was found to increase both friction coefficient and wear level. The wear tracks and wear debris were analyzed by scanning electron microscopy (SEM), energy disperse X-ray spectrometry (EDX) and X-ray diffraction (XRD). The observed mechanisms of wear are discussed with respect to the magnitude of wear that was measured.