Low Immersion Milling Simulation and Prediction of Stability

Milling processes are becoming one of the common manufacturing methods in industry. One of the main goals in any manufacturing operation is to increase productivity. In high speed low immersion milling, the ratio of cutting edge engaging time to spindle period is a small value. For this kind of operations, two types of: Instability are proposed: classical Hopf and the Flip bifurcation, which are mainly due to impact effects of entering/exiting of the cutting edge into the cut. In order to increase productivity, it is essential to anticipate stable machining boundaries. In this research, the main goal is to derive and implement the improved TFEA method to include the effects of the helix angle variations for a 2-DOF vibratory system and accurately compute the stability lobe diagram. Results obtained by simulation witnesses that instability due to Flip bifurcation vanish completely from stability lobe diagram with increasing helix angle to 30°. Experimental tests are conducted in order to confirm the result obtained by the improved TFEA method showing good agreements.