Study on the process damping in milling of thin-walled Ti-6Al-4V workpiece: Modeling, analysis, and prediction

Due to limited stiffness and wall thickness, chatter usually occurs in the milling of thin-walled components, which reduces the surface quality and machining productivity. It is well acknowledged that process damping, which results from the interference between the flank face and the machined surface, can improve the chatter stability. This paper analyzes the influence of process damping on the milling system of thin-walled Ti-6Al-4V alloy based on the Nyquist criterion and the Routh criterion. Meanwhile, a detailed and improved calculation model of the interference area is presented to promote the prediction accuracy of process damping. The comparison of computational results and experimental findings verifies the accuracy of the proposed model. The decrease of spindle speed increases the interference area as well as the total damping of the milling system. When the spindle speed is 1000 rpm, the ultimate stable axial depth of cut increases from 1.2 mm to 2.7 mm by utilizing the special designed end mills based on the presented model.