Machining Process Parameters Optimization Of Web Plates For Titanium Alloy Thin-walled Workpiece

With the rapid development of China’s aviation manufacturing industry, titanium alloy with its excellent comprehensive properties and structure characteristics is widely used, but titanium alloy is hard to be processed and titanium alloy thin wall parts has small wall thickness, relatively high material removal rate, under the influence of various conditions, especially the effect of cutting force, machining deformation occurs easily, and the cutting efficiency is poor, so it also has a great impact on the processing precision, performance and processing costs of parts and so on. Different machining parameters make the cutting force between the tool and the workpiece different, so the deformation and the efficiency of processing of titanium alloy thin-walled parts is different. Therefore, it is very important to select the optimal cutting parameters for the machining of titanium alloy thin-walled parts. In this paper, the characteristics of the web of titanium alloy thin-walled parts are the research objects, cutting force modeling, deformation prediction, multi-objective optimization and other aspects are researched, the main work completed is as follows.(1)Starting from orthogonal cutting analysis, the mechanism of oblique cutting is analyzed deeply, and the precise oblique cutting force model is presented. According to the characteristics of the web milling processing, based on the analysis of helical blade milling cutter geometry model, the transient model of milling force is analyzed, the relational model of model constants and cutting parameters is established, and the average cutting force is determined by the cutting experiments. Based on the analysis of the cutting parameters, according to the axial and radial cutting depth, the transient model parameters are obtained and the flexible cutting force model constants were solved.(2)Based on the accurate cutting force model, the finite element modeling, load processing and simulation analysis are carried out for the machining process of the titanium alloy web. At first, the test points are established at the same distance along the web length and the width direction. The same force is loaded, and then the deformation law of the web is analyzed to find the maximum deformation. Then, the mapping relationship between the cutting force and the maximum deformation of the web was simulated using the finite element software. Finally, using orthogonal polynomial least square method, the relationship between cutting force and the maximum deformation of the web is proposed to synthesize a function relation, which can provide data support for the optimization of web processing parameters of titanium alloy thin-walled parts.(3)Through the research on the basic principle of genetic algorithm, after the milling parameters optimization design variables of titanium alloy thin-walled webs, objective function and constraint conditions are determined, the parameter optimization model is constructed. The cutting parameters are optimized by using theMATLAB genetic algorithm toolbox in order to minimize the maximum deformation and the machining time.(4)The optimization results are verified by the experiments, using the experimental equipment and the measuring instrument, and the optimization results of the parameters of the web processing of titanium alloy thin-walled parts are verified. By measuring the time of machining and the maximum deformation of the web, the results of the optimization model of the web of titanium alloy thin-walled parts are compared and analyzed, which verified the correctness of the optimization results.Through the research of the above theories and methods, a model for optimizing the process parameters of the web of thin-wall parts is established, and optimized result is obtained. The verification experiment is designed, the experimental results and the optimization results are compared and analyzed and the reliability of the optimization results is proved.