Cutting Force and Energy Modelling in Ultra-Precision Machining of Micro-structures

Abstract

Cutting force and energy are usually used as important criteria for the selection and optimization of the ultraprecision machining parameters. Effective strategies for minimizing the cutting force and energy are becoming increasingly vital to meet sustainable manufacturing requirements. This chapter focuses on the prediction and validation of cutting forces and energies in ultra-precision machining of micro-structural surfaces on difficult-to-cut materials such as titanium alloy and brittle silicon. In the introduction, the current technical status of cutting force and cutting energy models is reviewed and some critical issues are described in the machining process. Then, the evaluation of cutting forces for fabricating microgrooves on titanium alloys is discussed with respect to material constitutive models and geometrical relationships. The predicted cutting forces are in good agreement with the measured cutting forces at various cutting conditions within an error of about 3.53%, and the equivalent stress required to overcome the plastic deformation of the titanium alloys increases with the cutting speeds because of the high dislocation drag stress. Next, the cutting energy in ultraprecision machining of micro-lens arrays (MLAs) on single crystal silicon by slow tool servo is discussed in terms of material ductile and brittle removal processes. It is clarified that the total material removal energy decreases with the increasing of feedrates, but the maximum material removal energy increases with the feedrates. The formation mechanism of the surface damage and its effects on the cutting energies are also discussed concerning crystalline orientations and surface energy of the silicon.