Prediction And Experimental Analysis Of Surface Topography In 5-axis Ball-end Milling

The parts,in automotive,aerospace,die/mold industry,which have extremely high demands on the quality and integrity of the surface,are usually milled by CNC machine tools.In order to obtain the desirable surface quality,it is an effective way to choose the appropriate cutting parameters before machining by simulating the surface topography and predicting the surface roughness formed in the milling process.To do so,this paper develops a model based on swept surface of cutting edge for predicting the surface topography and studies the effect of various cutting parameters.In this developed model programmed by Matlab,the mathematical equation of the cutting edge is first given,and then based on the relative motion between the cutter and the workpiece,the swept surface of the cutting edge of cutter along the tool path is analyzed and modeled accurately from the view of kinematics,which is here used to describe more realistically the cutting interaction of the cutter-workpiece.Subsequently,an improved Z-map model is adopted to create the topography of the machined surface.The algorithm is implemented by VC++.This procedure presents the advantage that solving a large number of nonlinear equations is avoided.On basis of this model,the effect of the cutting parameters,such as spindle speed,feed rate,inclination angle,cutter runout,etc.,is investigated.Finally,the real machining experiments are performed and compared with the predicted results.It is found that the simulated surface topography by the model show a good agreement with the real one,thus being able to accurately predict the machined surface topography.In order to make the research work have practical application.A simulation test platform based on iSIGHT is built in this paper.Through the platform,the influence factors,which include feed rate per tooth,path interval,tilt angle and cutter runout,on the surface roughness is studied by the method of factorial design.The main effect and interaction of the main factors of the surface topography and roughness are analyzed in detail by ANOVA.This paper fully explains the formation process and mechanism of surface topography,and a general principle of selecting cutting parameters in the actual industrial production is given according to the effects of the parameters on the surface quality,which has important reference value for the selection of processing parameters in industrial production.