Modelling and verification of stability of micro-milling process

In micro milling, the inherent instability of the cutting process limits the different combinations of parameters to achieve the required material removal rate and surface roughness. A stability lobe diagram shows the boundary between chatter-free machining operations and unstable processes, in terms of axial depth of cut as a function of spindle speed. These diagrams are used to select chatter-free combinations of machining parameters. Time domain simulation models of milling can be used to predict chatter and construct such stability charts. Hence, a chatter prediction model incorporating feed rate influence along with spindle speed and depth of cut, will be helpful. In the present work, time domain simulations of micro-milling were performed and chatter was predicted for three different feed rate conditions. Subsequently, this was validated with experiments by machining series of slots using 1 mm solid carbide end-mill on brass workpiece. There is good agreement between experimental and simulated results.