Investigations on piezo actuator-based nonresonant type workpiece vibratory system for vibration-assisted micro-milling

Abstract

Vibration-assisted micro-milling has emerged as a promising technique in Vibration Assisted Machining, aiming to enhance machining quality by applying small-amplitude high-frequency vibrations to the workpiece during micro-milling operations. This paper presents a novel design of a piezo actuator-based non-resonant type workpiece vibratory system specifically designed for 2-D vibration-assisted micro-milling application. The developed system is experimentally evaluated by generating 2D vibrations, considering each axis's cross-coupling and hysteresis displacements, at various actuation frequencies ranging from 100 Hz to 600 Hz. The application of the proposed setup focuses on the micro-milling of slots on an aluminium 6061 workpiece sample, utilizing 2D sinusoidal out-of-phase vibrations along x and y directions with a peak-to-valley amplitude of 10 µm. The cutting force data is collected and recorded by a tool force dynamometer, and the root mean square value of the cutting force is used as a parameter to compare conventional micro-milling with vibration-assisted micro-milling processes. In addition, the study compares the average surface roughness of the milled slots when using vibration assistance and without it. The experimental results demonstrate a significant decrease in cutting force and an improvement in the average surface roughness of the milled slot when implementing 2-D vibration-assisted micro-milling. These findings highlight the significance of the design, characterization, applicability, and suitability of the proposed non-resonant workpiece vibratory system in the field of vibration-assisted micro-milling process.