Ultrasonic elliptical vibration cutting of titanium alloy Ti–6Al–4V is investigated in this research. Because products made of Ti–6Al–4V alloy are usually designed for possessing low-rigidity structures or good-quality cut surfaces, machining requirements such as low cutting forces and slow rate of tool wear need to be fulfilled for realization of their precision machining. Therefore, the ultrasonic elliptical vibration cutting is applied as a novel machining method for those products. Machinability of Ti–6Al–4V alloy by the ultrasonic elliptical vibration cutting with cemented carbide tools is examined to figure out suitable cutting conditions for precision machining of Ti–6Al–4V alloy. As experimental results, generated chips, cutting forces, and profiles of cut surfaces are indicated. A forced vibration problem occurred due to the segmented chip formation, which is also well-known in the ordinary non-vibration cutting. Therefore, characteristics of the forced vibration due to the chip segmentation are investigated in this research. Through the experiments, it is found that the frequency and magnitude of the forced vibration have relation with the average uncut chip thickness and cutting width. Especially, it is found that the averaging effect can suppress the forced vibration, i.e. the chip segmentation tends to occur randomly over the large cutting width, and hence the force fluctuations with random phases tend to cancel each other as the cutting width increases relatively against the average uncut chip thickness. Based on the investigations, a new practical strategy to suppress the forced vibration due to chip segmentation is proposed and verified. Using the proposed method significantly decreased cutting forces and good quality of surfaces are obtained when the forced vibration is suppressed compared to the ordinary non-vibration cutting results. Therefore, the results suggest that the precision machining can be realized without sacrificing the machining efficiency by increasing the width of cut and decreasing the average uncut chip thickness.

本研究对钛合金Ti-6Al-4V的超声椭圆振动切削进行了研究。因为由Ti–6Al–4V合金制成的产品通常设计为具有低刚性结构或高质量的切削表面，所以要实现其精密加工，就必须满足诸如切削力低和刀具磨损速度慢的加工要求。因此，超声波椭圆振动切削被用作这些产品的新型加工方法。研究了用硬质合金刀具通过超声椭圆振动切削加工Ti-6Al-4V合金的可加工性，以确定适合于Ti-6Al-4V合金精密加工的切削条件。作为实验结果，显示了产生的切屑，切削力和切削表面的轮廓。由于切屑的形成而产生了强制振动问题，这在普通的非振动切削中也是众所周知的。因此，在本研究中研究了由于切屑分割而引起的强制振动的特性。通过实验发现，强迫振动的频率和幅度与平均未切屑厚度和切屑宽度有关。特别地，发现平均效应可以抑制强制振动，即，在较大的切削宽度上趋于随机发生切屑分割，因此，随着切削宽度相对于切削刃的相对增大，具有随机相位的力波动趋于彼此抵消。平均未切屑厚度。根据调查，提出并验证了一种新的抑制切屑切屑引起的强迫振动的实用策略。与普通的非振动切削结果相比，使用所提出的方法可以显着降低切削力，并在抑制强制振动时获得良好的表面质量。因此，结果表明，通过增加切削宽度并减小平均未切削切屑厚度，可以在不牺牲加工效率的情况下实现精密加工。