Fabrication and performance evaluation of metal bond diamond tools based on aluminothermic reaction

Abstract

Herein, the fabrication of metal bond diamond tools is proposed by using the Fe2O3-Al aluminothermic reaction. Moreover, the influence of sintering temperature and TiH2- and Si-doping on phase composition and mechanical properties of the reactive sintered bond is investigated. Furthermore, the grinding performance of metal bond diamond tool on ceramic tile is also examined. At 930 °C, the sintered bond is composed of Fe, Al2O3, Fe3O4 and FeO phases. However, the aluminothermic reaction initiated at 1028.8 °C and resulted in the formation of FeAl2O4 and Fe3Al phases. Moreover, the content of Al2O3, Fe3Al, α-Fe and FeAl2O4 phases increased with the increase of sintering temperature. The maximum flexural strength, hardness and relative density are achieved when sintering at 1230 °C. In addition, the dehydrogenation of TiH2 can impede the formation of FeAl2O4 phases and improve the flexural strength, hardness and relative density of the bond. Also, the Si-doping into Fe2O3-Al aluminothermic reaction system resulted in Fe2Al3Si3 phase and reduced the content of Al2O3 and Fe3Al phases, leading to higher flexural strength, lower hardness and inferior relative density. In wet grinding, the as-prepared metal bond diamond tool can be used to grind ceramic tiles with lower grinding force and better surface quality than the dry grinding. However, the as-prepared metal bond diamond tool rendered low wear resistance due to the brittle nature of the metal bond.