Prediction And Experimental Study On The Chatter Stability In Milling Of Thin Part

The rapid development of modern industry,so aerospace products with the advantages of high accuracy and high efficient manufacturing technology continue to bring forth the new through the old,the competition of market is more and more fierce.And aviation aluminium alloys are widely applied to aerospace thin-walled workpiece.But,because of its thin-walled workpiece with thin walls,poor rigidity,thickness change,large allowance and other characteristics,machining process is easy to produce chatter.It will not only reduce the machining accuracy of thin-walled workpiece,have a strong influence on machine tool and tool life,but also seriously restricted the cutting efficiency.Therefore,for example,the aluminum alloy 7075-T6 thin part,and research on the chatter stability of the milling process.Firstly,for the ball the-end mill,establish its milling instantaneous undeformed thickness model,and establish flexible workpiece milling system dynamics model considering the regeneration effect.Then,the paper analyzes the main factors which influence the stability of thin part milling.According to the characteristics of poor stiffness and difficult to machining for thin part,doing analysis by the fully discrete method to obtain the corresponding chatter stability lobe,to achieve the effect of processing parameters on stability prediction.And it is the based on the single degree of freedom dynamic model,at the same time,to study the dynamic characteristics of workpiece(modal stiffness,natural frequency and damping ratio)influence on chatter stability based on the fully discrete method and controlling variable method.Studies have shown that the larger stiffness,damping ratio and natural frequency is beneficial to the stability of milling process.But there are differences in the influence degree.Thirdly,study on the relationship between milling force coefficient and tool wear,according to different stages of milling tool wear,establish the corresponding two degree of freedom dynamic model.And the chatter stability predicted by fully discrete method,analysis of different tool wear effects on chatter stability.Meanwhile,considering the change of thin part thickness in the process,study on the tool wear effects on the milling process stability of different thin part thickness.Finally,based on the experiment of 7075-T6 thin part milling chatter stability study,which established the nonlinear milling chatter stability criterion,and compared with the fully discrete method to verify the reliability of the criterion.In this paper,the research can guide aluminum alloy ball end milling parameter optimization,and has a certain significance to the research of the chatter stability of milling.