Research On Cutting Performance And Cutting Parameters Optimization Of Superhard Tools In Cutting Superhard Aluminum Alloy

Due to its advantages of high hardness,high strength,low density and excellent mechanical properties,superhard aluminum alloy is widely used in aviation,aerospace,rail transit,automobile and other fields.PCD tool has the characteristics of high hardness,good wear resistance,good thermal conductivity,low thermal expansion coefficient and low affinity with non-ferrous metals.It is suitable for finishing and Superfinishing of non-ferrous metals.In this paper,Al7075-T6 is taken as the cutting object,the cutting force and surface roughness of PCD tool turning superhard aluminum alloy are studied by means of simulation and experiment,and the cutting parameters are optimized.The main research contents are as follows:(1)Finite element simulation and experimental verification of PCD tool turning superhard aluminum alloy were carried out.The influence of rake angle,clearance angle and arc radius of tool tip on three-dimensional cutting force is analyzed by single factor test method,and the geometric parameters of the above-mentioned tools are optimized based on the analysis results;the influence of cutting depth,feed speed and cutting speed on three-dimensional cutting force is analyzed by orthogonal test and single factor test;the accuracy of finite element simulation is verified by turning experiment.The results show that the reasonable geometric parameters of the cutting tool are the rake angle of 3 ~6,the clearance angle of 7,the arc radius of tool tip of 0.6 mm;the cutting depth and feed speed are the main factors affecting the cutting force;and the accuracy of the finite element simulation of the three-dimensional cutting force is more than 90%.(2)The cutting test of PCD tool for turning superhard aluminum alloy was carried out.Firstly,the cutting test scheme of PCD tool turning superhard aluminum alloy based on full factor test method is designed.Then,the turning test platform is built,and the turning test and test data are measured.Finally,the influence degree and rule of each cutting parameter on surface roughness are analyzed based on the test results.The results show that there is no interaction between the cutting parameters.The influence of cutting depth and cutting speed on the surface roughness is very small,and the influence of feed on the surface roughness is very obvious.(3)The prediction model of cutting force and surface roughness is established.Based on exponential function,linear polynomial function,non-linear polynomial function and BP neural network,the prediction models of cutting force and surface roughness are established,and the significance of each prediction model is tested.Finally,the prediction accuracy of each prediction model is compared and analyzed.The results show that each prediction model has good goodness of fit;the prediction model based on BP neural network has the highest prediction accuracy of threedimensional cutting force,which is more than 90%;the prediction model based on exponential function has the highest prediction accuracy of surface roughness,reaching 92.19%.(4)The optimization of cutting parameters for turning superhard aluminum alloy with PCD tools is realized.Firstly,the cutting parameters optimization model of PCD tool turning superhard aluminum alloy was established.Then,the cutting parameters were optimized based on linear weighting method and multi-objective genetic algorithm,and the two optimization results were compared and analyzed.The results show that the optimization of cutting parameters based on multiobjective genetic algorithm has more practical guiding significance for cutting.The research results of this paper are also have reference significance for superhard tools to cut other brands of superhard aluminum alloys.The research contents of this paper provide the application basis for building a more perfect evaluation system of superhard tools cutting performance.The research methods in this paper will provide a new way of thinking and theoretical basis for the future research on the cutting performance and of superhard cutting tools to cut ferrous or non-ferrous metals and the optimization of their parameters.