TC4钛合金低频振动钻削切屑形态和钻削力研究

为研究TC4钛合金低频振动钻削过程中切屑形态与钻削参数和振动参数对钻削力(轴向力和扭矩)的影响规律,基于一种自主研制的低频振动刀柄,分别采用单因素法和正交试验法对钛合金进行了低频振动钻削试验,分析了不同钻削条件下的切屑形态和钻削力,建立了轴向力和扭矩的经验公式,并对钻削力的影响因素进行直观分析与方差分析。结果表明:试验系统在低频振动钻削TC4钛合金时,振幅与进给量之比接近临界断屑值0.81时断屑可靠,排屑顺畅;低频振动瞬时钻削力呈现出规律的正弦波形,钻削力动态分量远大于普通钻削,轴向力和扭矩均值可比普通钻削分别降低10%～15%和15%～20%;进给量对钻削力影响最为显著,振幅次之,钻削速度影响最小;建立的振动钻削经验模型误差保持在10%以内,可以较为准确地对该试验系统所选参数范围内的钻削力进行预测。

Study on Chip Shapes and Drilling Forces of Low Frequency Vibration Drilling of TC4 Titanium Alloy

In order to study the chip shapes and the influence law of drilling parameters and vibration parameters on drilling forces (thrust force and torque) during low frequency vibration drilling of TC4 titanium alloy. Based on a self-developed low-frequency vibrating tool holder, low-frequency vibration drilling tests of titanium alloy were carried out by single factor method and orthogonal test method respectively. Chip shapes and drilling forces under different drilling conditions were analyzed. Empirical formulas of thrust force and torque were established. The influence factors of drilling forces were analyzed by visual analyses and variance analyses. Results show that when TC4 titanium alloy is drilled in low frequency vibration, the ratio of amplitude and feed is close to the critical chip breaking value of 0.81, the chip breaking is reliable, and the chip discharging is smooth. The instantaneous drilling force of low frequency vibration presents regular sine wave, and the dynamic component of drilling force is much larger than the ordinary drilling. The thrust force and torque mean may be reduced by  10%~15% and 15%~20% respectively than that of the ordinary drilling. The feed rate has the most significant influences on the drilling forces, the amplitude takes second place, the drilling speed has the least influence. The established vibration drilling experience model error is kept within 10%, which may accurately predict the drilling forces within the selected parameters of the test systems.