Microscale viscous sintering model application to the preparation of metal bonded diamond grinding wheels

Abstract

During sintering, with the interfacial free energy decreasing, particles bond to each other and the dense density increases, which are familiar phenomena in the preparation of metal bond diamond wheels and affect the mechanical properties of the grinding wheel. Herein, a sintering model of metal bond diamond wheels at a microscopic scale was constructed based on the computational fluid dynamics (CFD) and discrete element method (DEM), which was carried out to reveal the flow field, pressure field, and kinetic properties of the metal material in the heating process. Meanwhile, the finite element method (FEM) was used to analyze the thermal stress of diamond particles. The results show that with the increase in temperature, the viscous flow of particles intensifies. In the middle and late stages of sintering, the porosity of the particles changes significantly, and the densification rate is accelerated. Under the same temperature conditions, compared with the dodecahedral diamond, the octahedron produces less thermal stress and has better mechanical properties.