切削参数对TC4切削过程中刀具振动的影响

Effect of Cutting Parameters on Tool Vibration During TC4 Cutting Process

采用单因素法,对试验工件(其材料为钛合金TC4棒料)进行切削试验,通过测量刀具振动加速度并观察切屑形态,研究了刀具振动特性。研究结果表明:当切削速度较低时,工件被加工面的材料应变硬化起主导作用,刀具振动加速度的波动较大;随着切削速度的提高,工件被加工面的材料热软化逐渐起主导作用,且锯齿形切屑单元滑移导致的切削力波动的作用会逐渐变得迟缓,从而会减小刀具振动加速度的波动;在其他切削参数不变而只增大进给量或背吃刀量时,刀具与工件的接触面积会增大,被加工面的材料变形抗力也会增大;在形成锯齿形切屑时,切削力会瞬间降低,刀具会因受力失稳而振动增大。

Through the single-factor method,cutting tests are carried out on test workpieces(made of TC4 titanium alloy rod material).The characteristics of tool vibration are studied by measuring the vibration acceleration of the tool and observing the morphology of the chips.The study shows that when the cutting speed is low,strain hardening of the material on the machined workpiece surface predominates,leading to greater fluctuations in the vibration acceleration of the tool.As the cutting speed increases,thermal softening of the machined surface material gradually becomes dominant,and the effect of cutting force fluctuations caused by the slip of serrated chip units becomes more gradual,which reduces the fluctuations in the vibration acceleration of the tool.When other cutting parameters remain constant and only the feed rate or back engagement of the cutting edge amount is increased,the contact area between the tool and the workpiece increases,as does the deformation resistance of the material on the machined surface.When serrated chips are formed,the cutting force drops momentarily,and the tool vibrates more due to instability caused by the force.