| TC4 titanium alloy material is widely used in aerospace and other fields due to its high strength,low density and good corrosion resistance.Taking considerations of the TC4 titanium alloy thin-walled parts as the research object,the dynamic simulation model of milling processing was established by using the finite element method,and the influence law of milling parameters on milling force,milling temperature and workpiece machining deformation was analyzed.Through the optimization of milling parameters,the machining deformation was reduced and the machining quality was improved,The optimization results were verified by experiments.The main research contents were as follows:First,the variation characteristics of cutting force and cutting heat in high-speed machining of titanium alloy workpieces were studied,the methods and characteristics of milling were analyzed,and the key technologies involved in milling simulation were determined,including material constitutive model,failure criterion and cutter-chip friction criterion.Secondly,the dynamic simulation model of milling processing was established to analyze the change trend and cloud map distribution of physical quantities such as the stress of the workpiece in the processing of thin-walled parts,the temperature of the tool-part contact area,the milling force and the deformation of the milling process,and explain from the principle and model structure.Changes in chip separation,milling temperature and workpiece deformation.The accuracy of the simulation model was verified,and the absolute value of the relative error did not exceed 10%.The establishment of the simulation model prepares for the analysis of the influence of milling parameters on physical quantities such as milling force,milling temperature and machining deformation.Thirdly,taking considerations of the spindle speed,feed per tooth,axial depth of cut,and radial depth of cut as the research objects,the single factor analysis of the milling process was carried out,and the variation trends and causes of physical quantities such as milling force,milling temperature and machining deformation under different milling parameters were studied.It provides a basis for changing the milling force,milling temperature or workpiece machining deformation during the actual machining by controlling a single milling parameter.Finally,the orthogonal test table of milling parameters was designed,and the range analysis was carried out on the test results of the three indexes of milling force,milling temperature and workpiece machining deformation.The primary and secondary order of the influence of milling parameters on the three indexes was obtained,as well as the optimal parameter scheme to minimize the value of each index.The matrix analysis method was used to calculate the weight of each factor and level on the test results,and the optimal parameter scheme of the orthogonal test was determined according to the weight,so that the three index values were reduced at the same time,and the optimized results were experimentally verified.The results show that the milling force was reduced by 7.2%,the milling temperature was reduced by 1.2%,and the machining deformation of the workpiece was reduced by 17.3%. |
