Research On Clamping Strategy And Deformation Control Method Of Pure Copper Thin-walled Wafer Components In Precision Turning Process

In the manufacture of equipment in aerospace,national defense industry and other fields,thin-walled planar parts have been widely used because of their advantages of light weight and material saving.However,with the characteristics of large diameter-thickness ratio and poor rigidity,the thin-walled planar parts are extremely prone to produce large deformation under the effect of all kinds of factors in the process of machining,which leads to the failure of the parts to meet the requirements of need.In this paper,aimed at pure copper thin-walled planar parts which are used in precision physical experiments,a low stress clamping strategy based on local bonding is proposed.Meanwhile,a finite element model of clamping deformation for the precision processing of pure copper thin-walled planar parts is established.Considering the non-uniform internal stress field of pure copper thin-walled planar parts and utilizing the material non-uniform removal technology,the deformation caused by stress prediction in precision machining oparations of pure copper thin-walled planar parts is completed,and the accuracy of the prediction model is verified by doing the precision turning experiment.On this basis,the optimization of adhesive clamping position is completed in order to reduce the machining deformation of pure copper thin-walled planar parts.The specific research contents are as follows:(1)The deformation of local bonding clamping of pure copper thin-walled planar parts is analyzed.From the perspective of decreasing the clamping deformation of pure copper thin-walled planar parts and reducing the differences of the deformation of parts that would happen while in loading and unloading process,and based on the cutting force test results of pure copper thin-walled planar parts and the shear strength test results of the adhesive,the method of determining the stable clamping of the pure copper thin-walled planar parts is given and a lattice-type local bonding clamping method is determined.Based on this clamping method,the local bonding clamping deformation of pure copper thin-walled planar parts is simulated using the finite element simulation technology.The result shows that the local bonding clamping can be well applied to the precision machining operations of pure copper thin-walled planar parts.(2)A prediction model of precision machining deformation caused by stress of thin-walled planar parts under the condition of the local bonding clamping is established.Facing the precision machining operations of pure copper thin-wall planar parts under the condition of the local adhesive clamping strategy,a deformation prediction model in precision machining operations caused by stress of thin-walled planar parts is established,as the process of multiple-pass cutting of pure copper thin-walled planar parts,the process of non-uniform material removal and the non-uniform internal stress field are considered.It is proved that the model can accurately predict the deformation caused by stress after the precision machining of pure copper thin-walled planar parts by utilizing a precision machining experiment of pure copper thin-wall planar parts.(3)An optimization method for minimizing the deformation of pure copper thin-walled planar parts in precision machining operations is proposed.From the perspective of improving the efficiency of optimization process,using the sample points constructed by the purified precision machining deformation prediction model caused by stress of pure copper thin-walled planar parts,and based on the support vector regression machine,a surrogate model of precision machining deformation amplitude of pure copper thin-walled planar parts relative to the position of adhesive clamp is established.With the goal of achieving the minimum deformation after the precision processing of the pure copper thin-walled planar parts,based on the established surrogate model,the optimized design of the adhesive clamp position is completed by utilizing the genetic algorithm,which greatly reduces the deformation amplitude after the precision processing of the pure copper thin-walled planar parts.(4)Completed the development of the software for optimizing the bonding clamping position of thin-walled planar parts.Using the GUIDE tool set in MATLAB,a software with functions of deformation prediction of thin-walled planar parts,construction of SVR surrogate model and optimization of bonding clamping position is developed,which can realize the stress deformation prediction and achieve the optimization of bonding clamping position of thin-walled planar parts and so on conveniently and quickly.