Dynamic Simulation And Experiment Analysis On Ultrasonic Vibration Micro Milling

Ultrasonic vibration micro milling(UVMM) is defined as a method that a periodical vibration is imposed to the cutting tool or the work-piece to obtain better cutting performance. It has changed the traditional cutting process and improved its surface quality.In the process of UVMM, the vibration may cause the change of cutting characteristic, so the establishment of UVMM and its dynamic analysis are very important for the research of processing stability and milling experiment.At first, combined the ultrasonic vibration cutting mechanism, a two-dimensional finite element model is established. Then the influence of edge radius, cutting speed and the vibration amplitude to the cutting processing are discussed after the motion parameters are set.According to the features of the traditional milling model, the processing dynamic model of UVAM is obtained. Through the simulation model and the finite element analysis method, the milling force and the tool stability are deeply involved.Taking two edges end mill for example, the theoretical analysis of tool edge trajectory was researched and the necessary conditions of the cutting tool edge separated from the work-piece repeatedly is proposed for ultrasonic vibration assisted end milling. Necessary conditions of the cutting tool edge separate from the work piece repeatedly is that the amplitude of ultrasonic vibration should be greater than half of per tooth feed, and cutting length in a tooth cutting period is unequal to integer multiples of ultrasonic vibration wavelength. Base on the theoretical analysis results, the milling scheme of groove is set to research the influence of feed per tooth, spindle speed and the vibration amplitude to surface roughness. The results shows that if the feed per tooth is smaller or the spindle speed is larger, the surface roughness will be greater than before, and the surface quality is as good as traditional high speed milling machining even though small speed is used. It obviously optimizes the milling process. Compared with the traditional milling, it is found that the surface quality of UVMM is better, and the higher of the vibration amplitude, the worse of the surface roughness.