Multi-objective Optimization Of Processing Parameters Of 7075 Aluminum Alloy Thin-walled Parts

Aluminum alloy thin-walled parts are widely used in aviation,aerospace and other fields,because it can be used to make complex structures and its weight is light.However,the processing quality and processing efficiency of aluminum alloy thin-walled parts are directly affected by reasons such as low hardness and weak rigidity.Theoretical analysis and experimental research show that reasonable selection of tool geometric parameters(rake angle)and cutting parameters can significantly improve processing quality and processing efficiency.In this paper,7075 aluminum alloy thin-walled part is the research object.Through the combination of finite element simulation and actual experiment,the law of the influence in 7075 aluminum alloy thin-walled parts from process parameters is explored.The above research can achieve the purpose of improving the processing quality and efficiency of 7075 aluminum alloy thin-walled parts.The main contents are as follows:1.Regarding the current problems in the aluminum alloy thin-walled parts processing,the research purpose of the subject is combined with a summary of domestic and foreign literature,the main research content and research plan of the subject are determined,which including technical route,test method and key technology,etc.2.Based on the basic ideas of theoretical basis of metal cutting and the finite element method,ABAQUS finite element simulation software is used to build a 7075 aluminum alloy cutting model.Through the cutting simulation model established by ABAQUS software,four selected factors are simulated including tool rake angle,cutting speed,cutting depth and feed rate of each tooth in single factor numerical of five levels.Results of numerical simulation are used to explore the influence of these factors on the cutting force and cutting temperature.Subsequently,the orthogonal test table is used to carry out the orthogonal test to quantify the influence of each factor on the cutting force and cutting temperature.3.The specific geometric angle tool of the later test was ground in using five-axis high-precision grinder.Then 27 sets of milling experiments are designed by the Box-Behnken test design method in the response surface method and the thin-walled frame part is used as the processing objects.The deformation and surface roughness of the 7075 aluminum alloy thin-walled parts after experimental processing are measured by the three-coordinate measuring instrument and the surface roughness measuring instrument.The second-order polynomial prediction models of the deformation and surface roughness of thin-walled parts with respect to process parameters are established,respectively.And rightness of prediction model is verified.Finally,the influence of tool rake angle and cutting parameters on milling deformation and the surface roughness of the 7075 aluminum alloy thin-walled part is explored by response surface analysis.4.On the basis of above research work,the process parameters optimization model is established.The second-order polynomial prediction models of cutting deformation and surface roughness are the basis of the optimization model.The objective of the optimization model are the minimum deformation and the maximum material removal rate of 7075 aluminum alloy thin-walled part,and the processing surface roughness value is the constraint condition.The results of multi-objective optimization are obtained by Genetic Algorithm to solve the optimization model.Ultimately,the effectiveness of related methods are verified by milling experiment of 7075 aluminum alloy thin-walled frame parts experiments and measurement results.