| The titanium alloy workpieces have been used widely in modern aircraft as the main bearing structures. However, with the dual machining difficulties of materials and structures, it is hard to ensure the size accuracy of titanium alloy thin-wall workpieces. This paper studies titanium alloy(Ti6Al4V) as the research object, and analyzes the milling deformation deeply combining FEM simulation technology. The main research works as follows:(1) Based on the theoretical analysis of the milling process, coupled with orthogonal regression experiments, build the milling force prediction model. The reliability of the model is verified though a series of milling experiment and the most error is below 24%;(2) Single factor tests of cutting parameters have been conducted to research the influence of parameters to the milling forces, the surface quality and the machining deformation. These results can provide technical basis for the following researches about milling process on control deformation;(3) Based on the FEM, two kinds of 3D simulation models have been built with the simulation software. One is the rigid model by loading milling force obtained from the force prediction model. The other one is the coupling model of thermal-mechanical. Some tests have been conducted to validate their accuracy and to compare their merits and defects. Experiment shows that the second model is more accurate to predict forces, quality of surfaces and stress; but it spends more time on the calculation. The deformation law is summarized to offer basis for further optimization of milling process.(4) With the goal of maximizing the stiffness of the milling area, combined process stiffness theory, basic experiment has been conducted to improve the stiffness of workpieces, tools, fixers and milling machines. And then a Ti-alloy thin-wall web is finished within the error box. At last, this paper offers a control strategy to solute the milling deformation of titanium alloy thin-wall web. |
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