The Study On Cutting Parameter Optimization Of CBN Cutting Tools In Hard Dry Cutting Conditions

Cubic boron nitride(CBN)is an ultra-hard cutting tool material with the characteristics of high hardness,high chemical inertness,and high thermal stability has been widely used in hard dry cutting process in recent years.Controlling the surface quality of the workpiece is an important problem in hard dry cutting process.The surface roughness and residual stresses are two important factors to characterize the surface quality.The cutting parameters in turning process have an important influence on the surface roughness and residual stresses.Therefore,the machined surface quality can be improved by optimizing the cutting parameters.Dry turning of cold work die steel Cr12 Mo V with CBN cutting tools was experimentally investigated using Taguchi orthogonal experiment method,in which the cutting speed,feed rate,depth of cut,and tool nose radius were considered as design variables.By making use of the nonlinear mapping ability of neural networks,coupled with the global searching ability of genetic algorithms,a model for predicting surface roughness was established and an optimal combination of cutting parameters and tool nose radius giving the minimum surface roughness was found.The minimum surface roughness value obtained by this method was respectively 7.1% and 17.2% lower than the values obtained from the Taguchi method and turning experiments.A 2-D finite element model for orthogonal cutting process was established and the process of dry turning of Cr12 Mo V and nickel-based superalloy GH169 with CBN cutting tools was simulated using software Advant Edge.The effect of cutting regimes and rake angle,clearance angle,and cutting edge radius on surface residual stresses was examined.A model for forecasting the maximum tensile residual stresses of GH169 was established using artificial neural network based on the finite element simulation results under various cutting regimes.And the combination of machining parameters giving the minimum tensile residual stresses of GH169 was obtained by using Taguchi method.The comprehensive influence of geometrical parameters of CBN cutting tools on cutting force,cutting temperature,and maximum residual tensile stresses was analyzed and calculated by using the matrix analysis method,and the optimal combination of geometrical parameters of cutting tools has been obtained.