A MODEL FOR LAPPING OF GLASS

Lapping of glass and other brittle materials is an important economic activity. Nevertheless, it has not received much scientific attention, despite the fact that it is also related to problems of wear (three-body abrasion). Therefore, lapping of glass has been analysed in terms of the concept of lateral fracture, by studying the influence of material parameters, namely Young's modulus, hardness and fracture toughness, on material removal and surface roughness for two different sets of experimental conditions. The concept was found to be well applicable, and was therefore used to develop a model of three-body abrasion by material removal via rolling and indenting abrasives. The model gives a good description of the two experiments. It allows an average normal force per abrasive to be determined from Preston's coefficient and the characteristics of the workpiece and abrasive.