Stability recognition for high-speed milling of TC4 thin-walled parts with curved surface

Abstract

TC4 thin-walled parts with curved surface are widely used in industrial applications, and the surface quality is a basic requirement to ensure the functional performance. Because of the low rigidity of thin-walled parts, the cutting vibration problem is commonly encountered which results in a bad surface quality. Meanwhile, the rigidity of the workpiece is continuously changing along with the cutting process which is sensitive to the thin-walled parts and induces a more complex cutting vibration. With the extensive usage of high-speed milling which has the advantage of small milling force, the cutting vibration becomes more severe due to the high frequency excitation for the thin-walled parts. To avoid the serious cutting vibration as well as improve the machining quality for high-speed milling of TC4 thin-walled parts with curved surface, the appropriate cutting parameters which influence cutting vibration directly are needed to be determined. Taking high-speed flank milling of TC4 arc-shaped thin-walled parts as an example, the stable domain is worked out on considering the rigidity variation of thin-walled parts. Meanwhile, the limit stable axial cutting depth is obtained based on the stability domain which is established by considering the rigidity variation of workpiece along with the machining process. The results show that the limit stable axial cutting depth is 9.69 mm, and the stable cutting process as well as the high-efficiency machining can be guaranteed simultaneously when selecting the axial cutting depth that is slightly smaller than the limit value. This research puts forward an effective approach for recognizing the stable axial cutting depth range for high-speed milling of thin-walled parts with curved surface. In addition, it provides guidance for superior-quality and high-efficiency machining process.