Study On Radial Hole-making Processes Of Titanium Alloy Pipe

Titanium alloy is widely used in various piping systems and rotary valves because of its excellent performance.The quality of the hole will directly affect the stability and reliability of liquid or gas transmission in the piping system,as the hole is usually used as a channel for media connection between these components.To further improve the quality of rotary valves and pipeline connection holes,this thesis researches radial helical milling of TC4 titanium alloy pipes and investigates the influence of various process parameters on the quality of hole making through analysis of helical milling mechanism,finite element simulation prediction,and experimental research.On the basis of this,a variable parameter hole-making and the hole-making scheme are proposed.The specific research contents of this thesis are as follows:(1)Comprehensive analysis of titanium alloy processing and the current situation of domestic and foreign research on the application of helical milling,and put forward the research idea of the helical milling for TC4 titanium alloy pipes.The kinematic analysis of helical milling hole is carried out,the mathematical model of the motion trajectory is established,and a three-dimensional simulation is carried out.Based on the simulation of the cutting volume during helical milling,the change law of plate and pipe cutting volume is compared.(2)Based on the finite element simulation software,the finite element simulation of the helical milling process of TC4 titanium alloy pipes was carried out to analyze the changes of stress,strain,entrance and exit burrs,and cutting force to provide a reference for the subsequent experimental research.(3)The cutting forces of helical milling of plates and pipes were compared under the same machining parameters to verify the prediction of cutting forces by cutting volume.The response surface method was used to plan and conduct experiments with the response values of burr height at the entrance,hole wall surface roughness,and hole diameter to analyze the variation pattern of response values under different parameters and to prefer the better combination of predicted process parameters.(4)Based on a better combination of process parameters,cutting force simulation of variable parameter hole making for titanium alloy pipes is carried out,and validation experiments are conducted to analyze the entrance and exit burr height,hole diameter,surface roughness,and microscopic morphology of the hole wall.(5)To expand the use of TC4 titanium alloy pipes to carry out through-hole production tests,forward cutting using variable parameters processing,reverse cutting to carry out single-factor experimental research,reverse cutting process simulation and analysis of the reverse cutting of each factor changes in the axial force,hole diameter and the impact of the entrance and exit burr law.In this thesis,the kinematic analysis,simulation,and experimental study of titanium alloy pipes based on helical milling have been carried out to obtain the influence law of relevant parameters and to obtain better process parameters for the reference of radial hole making of pipe parts of other materials.