Study On Machining Stability Of Thin-walled Titanium Alloy Component With Paraffin Reinforcement

Thin-walled titanium alloys are extensively used in aerospace industry because of light weight, high structrue strength. In milling processes of thin-walled titanium alloys, problems such as dimension error and vibration are usually caused beacause of the low stiffness of workpiece and poor processing technology. Under the influence of cutting force, cutting vibration and cutting heat, it may also leads to serious workpiece scrap. Cutting vibration is one of the key problems which restricted the efficient machining of thin-walled titanium alloy.By taking thin-walled titanium alloys as research object, the deformation characteristics of the thin-walled workpiece under transient cutting force was studied based on the static analysis; milling experiments with and without paraffin reinforcement were conducted to investigate the effect of paraffin reinforcement on cutting stability and surface integrity of the milling surface.1) The static model of titanium-paraffin system was established. The mechanical character and deformation characteristics of the thin-walled workpiece were studied under transient force based on the static analysis. Meantime, the deformation error of the workpiece with paraffin reinforcement was analyzed and the deformation mechanism was studied.2) Based on the dynamic theory of the cutting stability, high speed milling thin-walled titanium experiment was conducted to investigate the change tendency of the acceleration signals in the milling processes and the surface integrity of the milled surface. And the paraffin reinforcement mechanism was revealed which has a theoretical significance to study and control the cutting stability in high speed milling of thin-walled titanium workpiece.3) The model of modal analysis of thin-walled titanium alloy was established. Natural frequency and vibration model parameters were analyzed under various wall thickness. It was showed that wall thickness has an effect on the modal paramenters; natural frequency and vibration model was analyzed with paraffin reinforcement and it was indicated that paraffin reinforcement can improve the stiffness of the workpiece, and to some extent, the natural frequency was enhanced and the vibration model was improved.4) Milling experiments of the double-sided frame titanium component were conducted and the effect of stiffness of the workpiece and paraffin reinforcement on the cutting stability and machining accuracy and the mechanism was revealed.