Study On Cutting Vibration Characteristics Of Titanium Alloy And Its Influence On Surface Roughness

Various forms of vibration are generated during the cutting process.Various forms of vibration are combined and finally act on the tool,causing vibration of the tool.This is a normal phenomenon that is difficult to avoid,but its usually harmful.Furthermore high frequency vibration can increase the surface roughness.Therefore,it is necessary to study the influence of vibration on the surface roughness.In this paper based on theoretical analysis,experimental study and finite element simulation,the tool vibration and surface roughness are studied.The main research contents and results are as follows:(1)Single-factor and orthogonal dry-turning experiments were carried out on TA15 and TC4 titanium alloys.The vibration characteristics are described by the effective value of vibration acceleration.The influence of cutting amount on vibration is studied and the effect of cutting force on vibration and the influence of chip shape on vibration are discussed.Based on the theoretical calculation and experimental study of adiabatic shear expansion,the relationship between the vibration characteristics and adiabatic shear sensitivity is studied.The results show that :the cutting depth has the greatest influence on the vibration,followed by the feed rate and the cutting speed;There is a certain relationship between vibration and cutting force,and the change trend is similar.The high frequency vibration of cutting tool can cause the cutting force fluctuation.The fluctuation of cutting force can also cause the vibration of tool.The smaller the value of adiabatic shear extension energy,the stronger the adiabatic shear sensitivity,the more likely to produce sawtooth-shaped chips,the greater the vibration.On the contrary,the vibration is smaller.(2)The influence of cutting parameters on the surface roughness was studied by TA15 and TC4 titanium alloy surface roughness test,and the influence of vibration on the surface roughness was studied.The influence of feed rate on the surface roughness is the biggest,followed by the cutting depth and the cutting speed.The actual surface roughness is the result of the coupling of theoretical roughness and tool vibration,where the theoretical roughness is the effect of tool geometrical parameters and cutting amount on surface roughness.(3)The cutting process of high speed Ti-6Al-4V alloy was simulated by ABAQUS software.Especially the formation process of sawdust chip was analyzed from the view of total energy.The main conclusions are as follows: the total energy figure of sawtooth-shaped chip is increasing,which shows that the cutting process is a regular vibration process.The energy pattern is consistent with the formation of sawtooth-shaped chips,so the generation of Serrated chip leads to high-frequency vibration of the tool.(4)The relationship between vibration and surface roughness is studied by means of wavelet analysis and SPSS software.The results show that vibration is the main dynamic factor that affects the surface roughness,the correlation between vibration characteristics and surface roughness is strong and the variation trend is consistent.