Formation Mechanism Of Titanium Alloy Drilling Exit Burr And Experimental Research On Ultrasonic Vibration-Assisted Drilling

Titanium alloy materials are widely used in high-end fields such as aerospace,submarine survey,military industry and national defense due to their advantages of high strength,low density,corrosion resistance,and good fatigue resistance.However,its excellent material properties also lead to increased processing difficulty,resulting in problems such as faster tool wear,worse exit burr morphology,and larger size.As the manufacturing industry enters high-efficiency precision machining,the requirements for drilling quality and efficiency are gradually increasing,but the emergence of burrs at the exit of titanium alloy drilling seriously affects the drilling efficiency and reduces the surface quality and assembly accuracy of the holes.Aiming at the problem of exit burr in titanium alloy drilling,this paper analyzes the type,formation process and evaluation method of exit burr.Through the titanium alloy drilling experiment,it explored the effect of cutting parameters and tool wear on drilling force,exit burr morphology and size.Finally,the ultrasonic vibration drilling process is used for optimization,which provides a theoretical basis for the research on titanium alloy drilling exit burr.The main research contents are as follows:(1)The three types and formation process of titanium alloy drilling exit burr are studied and summarized,and evaluation method of titanium alloy drilling exit burr is analyzed,which provides a theoretical basis for the subsequent experimental research on cutting parameters,tool wear and process optimization of titanium alloy drilling.(2)Through experiment on the titanium alloy drilling exit burr,the change trend of axial force and torque with different cutting parameters is analyzed,and the influence of cutting parameters on the shape and size of the exit burr is explored.The results show that the axial force gradually decreases with the increase of the spindle speed and gradually increases with the increase of the feed rate.And to verify that with the establishment of a multivariate linear regression model of the axial force;With the increase of the spindle speed,the exit burr height first increases and then decreases;With the increase of feed rate,the height of the exit burr height rises in volatility;The type of exit burr is mainly uniform burr or uniform burr with drill cap.(3)Through the experiment on titanium alloy drilling tool wear,the type and wear mechanism of the tool wear are analyzed,and the relation between the tool wear and the shape and size of the exit burr is studied.The experiment shows that tool wear increase with the increase of spindle speed,and the change of feed rate has little effect on the tool wear;The size of the exit burr will increase with the increase of the degree of tool wear.And the type of exit burr will change from uniform burr to crown burr.Flanging burrs will be produced when the chips in the hole are blocked and then cause ablation.(4)After the research on effect of ultrasonic vibration-assisted drilling of titanium alloys on the exit burr,and compared with traditional drilling,it is concluded that the drilling force of ultrasonic vibration-assisted drilling of titanium alloys is significantly lower than that of traditional machining,and its exit burr morphology is smoother and flatter,and the height of the exit burr is also effectively reduced.