High-Aspect-Ratio Microdrilling Assisted by Ultrasonic Vibration

—High-Aspect-Ratio Microdrilling of Fuel Injection Nozzle—

Abstract

This study aimed to achieve the high-aspect-ratio microdrilling in L/D=20 by the addition of ultrasonic vibration during drilling. In the experiment in L/D=10, the amplitude of ultrasonic vibration from viewpoints of tool wear and thrust force are determined. The high-aspect-ratio microdrilling in L/D=20 was examined based on the processing conditions in L/D=10. The following results are obtained. The decrease of the cutting rate and the use of the microdrill with thinning are necessary to apply the supersonic vibration for high-aspect-ratio microdrilling in L/D=20.