Effect of crystallographic orientation on residual stress induced in micro-grinding

Abstract

In micro-grinding, the effect of material microstructure on residual stress is significant since the depth of cut is usually smaller than the average grain size. In this paper, the effect of crystallographic orientation (CO) on the distribution of residual stress induced by micro-grinding is investigated. The COs and their volume fractions of workpiece material are quantified by Taylor factor, based on which the models of flow stress and plastic modulus of polycrystalline materials are proposed. Then, the residual stress is calculated based on the micro-grinding force and temperature derived from the flow stress, after the mechanical and thermal loading followed by relaxation process, which are analyzed with the developed plastic modulus. Thereby, the compressive analytical model of micro-grinding-induced residual stress is proposed considering the grinding parameters, wheel topography, and material microstructure. In addition, micro-grinding experiments and residual stress measurements are conducted to verify the models. The prediction of residual stress agrees well with the experimental result. Residual stresses are measured by X-ray techniques, and the results illustrate that the COs of material would influence the state of stress. Finally, the sensitivity analysis is carried out, with the result showing that the effect of CO on residual stress is significant.