Quantitative analysis of the loads acting on the abrasive grits in the diamond sawing of granites

Abstract

An experimental study was carried out to evaluate quantitatively the loads acting on the diamond grits during the circular sawing of two kinds of typical granite with a diamond segmented saw blade. Measurements were made of the horizontal and vertical force components and the consumed power in order to obtain the tangential and the normal force components. The temperatures at the diamond–granite contact zone were measured using a foil thermocouple, the measurements, together with the net sawing power, being used subsequently to estimate the energy partition to the granite by a temperature matching technique. Based on the energy partition values, tip temperatures at individual cutting points were estimated using an analytical model. SEM was used to follow the topographies of worn diamond segments. The average force acting on each diamond grit was found to be only 4% of the diamond compressive strength measured by a static method. The strength disparity of diamond grits and the random protrusion of grits beyond the bond matrix should be significant factors in accounting for the wear of diamond grits. The wear of diamond grits was also found to be closely related to the high temperatures generated at individual cutting points and the pop-out of diamonds from the bond matrix were attributed to the heat conducted to the segments.