Finite element investigation on the evolution of wear and stresses in brazed CBN grits during grinding

Abstract

Finite element method (FEM) is a power tool to predict the stress distribution in the cubic boron nitride (CBN) grits, which are difficult to accurately characterize with the experimental methods due to rather small grit size of 100–400 μm. In this work, modeling techniques on the coupling effects of brazing-induced stresses and grinding-induced stresses in the brazed CBN grits are investigated by applying FEM code ABAQUS in order to understand the grit fracture wear. The stress evolution in the bottom surface, in the top surface, and in the tensile side of the CBN grits is discussed for six sequential wear stages. Results obtained reveal that, with the wear advance of the grit and bond, the effect of the grinding force on the resultant stresses is generally weak in the grit bottom surface, while the corresponding effect of the brazing-induced stresses is significant. Large magnitude of resultant stresses ranging from −754 to −1243 MPa is formed in the grit vertex region, which is the primary factor for grit micro-fracture during grinding. Meanwhile, large brazing-induced tensile stresses are usually obtained in the grit-bond junction region, which is the vital factor for grit macro-fracture in grinding.