Tool path planning and machining deformation compensation in high-speed milling for difficult-to-machine material thin-walled parts with curved surface

Abstract

Difficult-to-machine material thin-walled parts with curved surface are widely used in industrial applications, and the shape accuracy is a basic requirement for ensuring the usability. Due to the low rigidity of the thin-walled curved surface parts, the cutting force becomes a sensitive factor for the machining deformation. In addition, high speed milling, that has an obvious attribute of small cutting force comparing with the traditional one, provides an effective way to process the thin-walled curved surface parts made by difficult-to-machine materials like titanium alloy. Moreover, the rigidity of the thin-walled curved surface parts is constantly changing along with the machining process, which leads to a more complex machining deformation when choosing different tool paths and affects the machining quality. To reduce the machining deformation, a proper cutting parameters combination which influences the machining deformation directly is obtained based on the established cutting force model, and then a deformation control strategy by planning tool path is put forward. At the same time, an efficient compensation method based on modifying cutter location point is proposed. Taking TC4 thin-walled arc-shaped parts as an example, experimental studies indicate that the largest deformation values reduce to 49 μm after compensation. Compared with the former 104 μm, the deformation degree decreases by 52.88 % when the thickness of the thin wall is 200 μm. The research provides an effective approach to reduce the machining deformation induced error for difficult-to-machine material thin-walled parts with curved surface.