| Modern aircraft demands high strength of structure mass, high resistance to fatigue and someother requests, therefore, aerospace titanium alloy thin-wall parts have got extensive attention inairplane design. However, back-off of the workpiece locality, milling chatter is likely to occur whenmilling titanium alloy thin-wall parts. The phenomena above have bad impacts on the machiningprecision and shorten the life of cutter and machine tool. The theoretical analysis, numericalsimulation and experiments are combined to study the deformation of milling titanium alloy thin-wallparts. The control methods of the deformation of titanium alloy thin-wall parts are studied in aspect ofmachine process, and the milling processes are optimized comprehensively. The major research worksare listed as follows:Firstly, based on the theoretical analysis of milling process, coupled with orthogonal regressionexperiments, the milling force prediction model is built to research the change rules and thecharacteristic of distribution of the cutting force with the change of the cutting parameters. Based onthe metal removal mechanism, the reasons of the change law are revealed to provide basis foroptimizing cutting parameters.Secondly, basic experiments of milling titanium alloy thin-wall part has been conducted，whichinclude single factor experiment of the milling parameters and test experiment of the residual stress onthe thin-wall part. The single factor experiment studies the influence of the parameters to the millingforce and the surface quality. The residual stress test reveals the impact of the milling force to theresidual stress distribution.Thirdly, cooperated with the cutting force prediction model, with the usage of the simulationsoftware ANSYS, the machine deformation prediction model of the titanium alloy thin-wall parts isestablished to simulate the deformation of the thin-wall parts after its veracity being verified. Thedeformation law is summarized to offer the decision to further optimizing the milling process.Finally, aimed to reduce the machining tolerance, and coupled with the process system stiffnesstheory, the researches of how to reduce the cutting force and how to increase the process systemstiffness are studied respectively. Through the experiments, the guidance of optimizing the machinecondition to control the deformation of titanium alloy thin-wall parts is finally shaped. |
