Abstract: In micro-grinding, the effects of crystallography on grinding force become significant, since the depth of cut is less than the grain size. Consequently, the mechanism of micro-grinding is distinctive from the macro-grinding. The Taylor factor model for polycrystalline materials is proposed to quantify the crystallographic orientation (CO) with respect to the cutting direction by examining the number and type of activated slip systems. Then, the flow stress model is developed, based on which, the predictive model of chip formation force is proposed by adapting parallel-sided shear zone theory. The new approach for calculating the static grit density of grinding wheel is proposed based on the measurement of the wheel morphology. A comprehensive model is then proposed to predict the micro-grinding force by consolidating mechanical and thermal effects, crystallographic effects, the grinding wheel topography, and process parameters. An orthogonal-designed experiment is conducted to validate the force model, with the result proving that the prediction of the model is capable to capture the magnitude and trend of the experimental data.

Key words: micro-grinding, grinding force, crystallographic orientation, Taylor factor, flow stress, static grit density