The influence of abrasive body dimensions on single asperity wear

This work focuses on the relation between the properties of abrasive bodies and the wear they cause. By performing single asperity scratch tests to simulate abrasive wear, the wear process takes place in a controlled environment, allowing the properties of the abrasive body to be isolated and studied independently. The setup used is a pin-on-flat machine, enabling scratching along a straight line and under active load control. The abrasive bodies were generalised by using single crystal SiO2 tips to scratch DIN St-52 steel samples. The tip radius was varied to study the influence of the abrasive body size on the abrasive wear process. The normal load was varied as well to obtain its influence. Using confocal microscopy, the scratches were analysed to identify the abrasion mechanisms, such as ploughing and cutting and to determine the volumetric wear. As expected, the results show an expected increase in the wear volume with increasing load. More interestingly, the wear rate varies significantly as a function of the size of the abrasive, enabling the prediction of the wear rate based on the abrasive body size. It is observed that, contrary to earlier reported size effects, smaller tips cause more wear than larger tips do. Moreover, at the low values for the degree of penetration studied in this work, a regime of limited plastic deformation was identified, based on the observation that the degree of wear parameter decreases with increasing degree of penetration.