Micromilling Simulation for the Hard-to-cut Material

Micromilling of the hard-to-cut material has many challenges such as the relatively weak stiffness of the machining system and the deep understanding of the micromilling mechanism. Aiming at the typical hard-to-cut material Inconel 718, the model of micromilling process has been created based on FEM (finite element method). The analytical results of the FEM model show that the critical process parameter of minimum undeformed chip thickness (MUCT) is the critical feed engagement fz =1.5 μm/z for Inconel 718. The milling force shows a trend to increase with the increasement of feed engagement. The radial depth of cut ae has directed effects on the cutting force and it shows that the milling force has an obviously trend to increase with the increasement of radial depth of cut. Therefore, in micromilling of Inconel 718, the feed engagement should be larger than the critical value and the radial depth of cut is better to select a relatively smaller one in order to reduce the cutting force.