An environment-friendly metal bond diamond tool based on reactive sintered Fe3Al and grinding performance on ceramics

Abstract

Metal bond diamond tools have been extensively employed to grind a wide variety of hard and brittle materials. However, numerous heavy metal elements (e.g., Co, Cu, Ni, Cr, Sn and Zn) have been introduced into the metal bond to enhance the hardness and strength, so as to enhance the grinding performance of diamond tool. Some of the heavy metal elements pose a hazard to the environments and operators in the manufacturing and machining process of diamond tools. Herein, an environment-friendly metal bond was proposed for diamond tool based on the reactive sintered Fe3Al, which contained only the strengthening elements of Si, C, and Ti. The effect of sintering temperature on microstructure and mechanical properties of Fe3Al and the effect of adding C (graphite), Si, and Ti (TiH2) on the properties of the metal bond were investigated. A diamond tool was prepared based on the optimized composition and sintering parameter, and its grinding performance on Al2O3 and Si3N4 ceramics was compared with a commercial diamond tool. The results indicated that the hardness and flexural strength of bonded material increased with the sintering temperature and the content of the additives. The highest hardness and flexural strength were obtained for the bond containing 0.5% of graphite, 1% of Si, and 3% of TiH2 at the sintering temperature of 1250 °C. Compared with commercial diamond tool, the prepared diamond tool exhibited significantly lower grinding forces, similar grinding ratio for Al2O3 ceramic, and a slightly lower grinding ratio for Si3N4 ceramic.