Prediction of surface profile in single-point diamond turning of microgrooves: a novel model incorporating multiple elastic-plastic deformation mechanism

Single-point diamond turning is an efficient process for fabrication of submicron-level precision surface topography. Topography error seriously affects the performance of the designed function surface. Nevertheless, material elastic recovery and plastic side flow on machined surface would significantly affect the surface topography and machining precision. This paper aims to enhance the accuracy of diamond turning microgrooves by investigating the elastic-plastic deformation mechanism. Firstly, the stress distribution and material flow patterns are analyzed using finite element and analytical modeling. Secondly, a novel theoretical model for prediction of the microgroove cross-sectional profile is developed incorporating the multiple effects of tool profile, elastic recovery, and plastic side flow. Meanwhile elastic recovery and plastic side flow are analyzed and modeled respectively. Thirdly, the effects of machining parameters on material elastic-plastic deformation are discussed from the perspectives of stress and strain variations, and a quantitative method to analyze the elastic-plastic deformation of microgrooves is proposed. Finally, correction coefficients for machining parameters are introduced into the geometric model to improve the predictive accuracy of the proposed model. The results demonstrate that the machined surface profile obtained with proposed geometric model effectively aligns with actual microgroove profile, confirming its accuracy and practical applicability. This research enhances understanding of elastic-plastic deformation in diamond turning, and provides a theoretical foundation for enhancing microgroove accuracy in ductile materials.