The Influence Of The Tool Nose Radius On The Cutting Performance Of 7050 Aluminum Alloy Thin-walled Parts

Because of the advantages of compact structures,light qualities,great overall performance,material saving,pleasing shape and so on,thin-walled parts are becoming more widely used in the modern aerospace and national defense industry areas.But on the other side,thin-walled parts have the properties of poor stiffness and easy deformation,which make them difficult to be machined and a low rate to be formed.Researchers all across the world are paying their attentions to the forming characteristics and quality control methods of thin-walled parts through systematic theoretical analysis,they have discovered the numerous factors that make influence,which include:material and stiffness of workpieces,machine characteristics,clamping condition,residual stress and machining path.This paper aimed at milling analysis of the thin-walled parts made of 7050-T7451 aluminum alloy material.Synthetically considering the influence of tool nose radius,the author tried to build a milling force model with corner radius referring to the oblique cutting model;According to the heat transfer theory,the model of heat source intensity was built,which could be represented as::It is a Continuous and inclined line heat source along the cutting speed,with a certain heat flux;what was more,the milling temperature field was calculated.On the base of theories from DL.Mc Dowel and S.Y.Liang,additionally considering temperatures,the author built the residual stress model and transferred the residual stress on milling plane to the coordinate systems of workpieces according to correlation formulations.In order to validate correction of the built model,the author built milling 3D models of aluminum alloy thin-walled parts machined by different tool nose radiuses and used ABAQUS finite element software to do simulations.Through analyzing the cutting force on X,Y,Z axis during cutting process,the author finally found the rule of cutting force with time;Through analyzing the distribution of S,Mises stress on cutting surface and along cutting depth,the author concluded the rules and simulated the stress on X,Y,Z axis;Through analyzing the distribution of temperatures on cutting surface and along cutting depth,the author acquired the simulation rules.The author conducted experimental studies on simulation processes to make a comparison of built models.The author built real-time online monitoring system to observe 3D force and temperature and measured the residual stress,3D performance,hardness values and processing characteristics on the surfaces of workpieces after machining.Through changing the tool nose radiuses and cutting parameters during machining process,the author analyzed and acquired the influence rule of tool nose radiuses,feed ratios,revs,milling depth and width to 7050-T7451 aluminum alloy thin-walled parts properties.The author emphatically studied the processing characteristics of tool nose radiuses to force,temperature,residual stress and surface quality of 7050-T7451 aluminum alloy thin-walled parts to provide reference to practical machining.