Study on Influence of Ultrasonic Vibration on the Ultra-Precision Turning of Ti6Al4V Alloy Based on Simulation and Experiment

Abstract

Titanium alloy is one of the most important metals widely used in many industrial fields due to its special performance, such as high corrosion resistance and specific-strength. In recent years, titanium alloy has a great application prospect in the optical field. However, the pitiful machinability of titanium alloy material brings great difficulty to its ultra-precision cutting. In this paper, we have proposed the method of ultrasonic-assisted ultra-precision turning (UAUT) to improve the cutting performance of titanium alloy. In addition to exploring the mechanism of ultrasonic cutting, the purpose of this paper is to make a comprehensive comparison between UAUT and conventional ultra-precision turning (CUT) of Ti6Al4V alloy. The orthogonal cutting model was established using the software ABAQUS for revealing the cutting mechanism of titanium alloy. The effect of ultrasonic vibration on the chip morphology, cutting force, residual stress, and cutting temperature in the ultra-precision turning process of titanium alloy has been investigated by the finite-element model. The results of the simulation indicate that UAUT can reduce the cutting force, residual stress, and temperature as compared to that in CUT. The results of the simulation show a great agreement with the experimental results. Furthermore, the comparison of surface roughness and surface morphology between the UAUT and CUT experiments confirmed that the surface quality of the Ti6Al4V sample is improved obviously by ultrasonic vibration. At the same time, the results of the experiments show that the chips became more continuous, and the tool wear was reduced by the UAUT method. This research proved that the UAUT method can greatly improve the cutting performance of titanium alloy.