Study on the thermal wear of diamond segmented tools in circular sawing of granites

Abstract

An investigation is reported of an analysis on the thermally induced sawblade wear in circular sawing of granites with diamond segmented tools. The temperatures at the diamond–workpiece interface were measured in dry sawing using a foil thermocouple in order to examine the contribution of temperatures to the wear of the segments. Scanning electron microscope and energy dispersive spectrometers were employed to analyze the mechanisms for the bonding of Ti/Cr-coated diamonds to an iron-based matrix. Over 90% of the consumed energy was found to conduct into the diamond segments as heat in the sawing. Strong metallurgical bonding was observed at the diamond–matrix interface and subsequently the retention ability of the matrix to diamonds was increased. However, the retention effect of the coating was greatly offset by the disparity of diamond crystal strength, which could be improved by multistage shape selecting and magnetic separating. Coupled with the mechanisms for thermal wear, attempts were made to reduce thermally induced wear by using Ti/Cr-coated diamonds, reducing the disparity of diamond crystal strength, designing unique structured segments and selecting optimal machining parameters.