Chatter Suppression during Milling of Ti-6Al-4V Based on Variable Pitch Tool and Process Damping Effect

Abstract

Regenerative chatter is a major limitation in the milling of Ti-6Al-4V, resulting in undesirable surface and reducing cutting efficiency. It is well-acknowledged that variable pitch cutter and the process damping effect are effective methods to suppress chatter, and that these two methods are compatible. In this paper, a novel anti-vibration milling tool with combined variable pitch (pitch angles of 85°-95°-85°-95°) and wear edges (60 μm on the flank face), which helps to increase the process damping effect, is presented. The milling model of variable pitch tool considering process damping effect is developed and the dynamic milling stability is analyzed by using the semi-discretization method. To modify time delay, an analytical formula for optimal tuning variable pitch angles is presented. The effectiveness of the proposed anti-vibration tool is verified by stability diagrams and milling experiments. Industrial experimental results show that compared with the common regular pitch tool and onefold variable pitch tool, when the proposed anti-vibration tool is used, the stable axial depth of cut increases by 97.4% and 26.2%, respectively.