Analytical modeling of subsurface damage and material removal energy in elliptical vibration cutting of micro-structures on brittle materials

Abstract

Elliptical vibration cutting (EVC) is a promising technique for the fabrication of micro-structures on brittle materials. In this work, the surface quality and material removal energy in ultra-precision machining of micro-structures on brittle materials by EVC were investigated. Theoretical models were first established for predicting subsurface damage and specific cutting energy (SCE) based on the intermittent material removal characteristics of EVC. The models correlated cutting parameters with the tool vibration trajectory parameters, target surface geometry parameters, and material removal modes. Furthermore, the material removal behaviors in the nominal cutting direction and the feeding direction were comprehensively considered. To verify the model, the experiments of EVC and ordinary cutting (OC) were performed on single crystal silicon, and the surface morphology and cutting force were characterized. The results indicated that, compared with OC, the maximum subsurface damage depth is reduced by 61.82% and the SCE stability value is reduced to 45.87% by applying EVC to fabricate micro-structures. EVC could significantly improve the machining quality and reduce energy consumption. In addition, increasing the vibration amplitude in the depth of cut direction could further save energy, but a larger amplitude would increase subsurface damage. This work not only promotes the recognition of the material removal mechanism of EVC, but also presents effective guidance for achieving high-quality and sustainable machining of micro-structured surfaces.