Research On Chatter Stability And Machine Error Of Milling Titanium Alloy Thin-walled Parts

Milling, a main means of machining titanium alloy thin-walled parts, is widely used in aerospace industry. Chatter which is a kind of unstable phenomenon appeared in the milling does not only seriously impact on the machining quality and production efficiency, but also damage the tool, even destroy the machine tool spindle and reduce the machine tool’s life. Therefore, research on chatter stability and machine error of milling titanium alloy thin-walled parts has an important application value on improving the machining quality and efficiency.In this paper, the dynamic mechanical analysis and mechanical analysis were studied. The main content and achievements are as follows:(1) The cutting force model of ball end milling cutting is established to analysis the milling force on machining the titanium alloy thin-walled parts. Considering the dynamic regeneration force and process damping force, the cutting force model of ball end milling cutter is established and then the effect of cutter parameters and processing parameters is analyzed and simulated. The text is accomplished and the cutting force coefficients are obtained, then the cutting force model is verified.(2) Considering the regeneration effect in milling process, the 2-DOF dynamic model of milling was established. Introducing the relative transfer function, the milling chatter stability of machining the thin-walled parts was proposed and then the 3D chatter stability lobes was attainted in MATLAB. The effect on stability of the cutter parameters is also analyzed and simulated. In modal text, the modal parameters are obtained, and then the stability lobes are achieved based on the modal text.(3) On small radial immersion, the semi-discretization method was proposed based on the theory of dynamic milling model and stability analysis in time domain. Using the Floquet theory, the milling stability was analyzed. The effect on stability of model parameters was also analyzed.(4) The surface location error is predicted using the frequency domain method on the stable milling. According to the system response, the law of aeD and spindle speed affecting the SLE is analyzed. A ball end milling surface roughness model is established to predict the milling surface. Using the virtual simulation technology, the laws are analyzed which the effect of the ball end cutter radius and feed rate to the surface, providing the basis for process.