Micro-flank milling forces considering stiffness of thin-walled parts

Abstract

A novel micro-flank milling force prediction model is developed in this study by considering the deflection of tool and workpiece, tool run-out, and material strengthening effects during the flank milling of thin-walled parts. The model of the cutting tool applied in this study is closer to the actual structure and its deflection model is established based on Euler Bernoulli cantilever beam theory under mesoscale. The values of the workpiece deflection are obtained with an online Keyence LK-H020 laser sensor. The Johnson−Cook constitutive model is adopted to estimate the flow stress σ JC, which takes in consideration the effects that strain-hardening, strain-rate, and thermal softening have on the flow stress. The mechanistic model is validated by a series of micro-thin-wall experiments with a two-flute KENNA micro-milling cutter as tool and Ti-6Al-4V titanium alloy as workpiece material. Experimental results illustrate that the proposed model performs well for the micro-flank milling forces in the x-direction, with an average error of 4.153%, while the error in the y-direction is slightly larger at 4.458%.