Experimental Study on Ultrasonic Vibration-Assisted WECDM of Glass Microstructures with a High Aspect Ratio

Yan Chen,Gongming Xin,Xu Feng

doi:10.3390/mi12020125

Abstract

With the rapid development of micro-electro-mechanical systems (MEMSs), the demand for glass microstructure is increasing. For the purpose of achieving high quality and stable machining of glass microstructures with a high aspect ratio, ultrasonic vibration is applied into the micro-wire electrochemical discharge machining (WECDM), which is proposed as ultrasonic vibration-assisted WECDM with a micro helical electrode. Firstly, the formation of a gas film on the surface of the helical electrode in WECDM machining is simulated, meaning the thickness of the gas film can be reduced by adding suitable ultrasonic amplitude, thus reducing the critical voltage, then the machining localization and stability were enhanced. Then, the micro helical electrode with a diameter of 100 μm is used to carry out sets of experiments that study the influence of ultrasonic amplitude, machining voltage, duty factor, pulse frequency, and feed rate on the slit width. The experimental results show that the machining stability and quality are significantly improved by adding suitable ultrasonic amplitude. When the amplitude was 5.25 μm, the average slit width was reduced to 128.63 μm with a decrease of 20.78%. Finally, with the optimized machining parameters, micro planar coil structure and microcantilever structure with a high aspect ratio were fabricated successfully on the glass plate. It is proved that ultrasonic vibration-assisted WECDM with the micro helical electrode method can meet the requirements of high aspect ratio microstructure machining for hard and brittle materials.

Highlights

With the rapid development of micro-electro-mechanical systems (MEMSs), the demand for glass microstructures is increasing, due to their excellent properties
Wire electrochemical discharge machining (WECDM) is a kind of non-contact machining, which can overcome its hard brittleness and non-conductive characteristics, so it can be competent for the machining of glass, a kind of non-conductive hard, brittle insulating material [4,5]
Ultrasonic vibration can bring huge gain effect for the quality of WECDM, so this paper introduces ultrasonic vibration into the micro-WECDM, and innovatively puts forward the micro helical electrode ultrasonic vibration-assisted WECDM method, to solve the problem of machining glass complex micro planar coil structure and high aspect ratio microcantilever structure

Summary

Introduction

With the rapid development of micro-electro-mechanical systems (MEMSs), the demand for glass microstructures is increasing, due to their excellent properties. Many scholars have been actively engaged in the field of electrochemical discharge machining (ECDM) and achieved certain results. Kim et al [7] studied the influence of pulse frequency and duty factor on glass machining by ECDM using a pulse power supply. Nguyen et al [8] studied the microstructure of ECDM ceramics and discussed the influences of electrolyte level and concentration, pulse voltage, pulse opening and closing time, and tool feed rate on the machining performance. Hajian [9] studied the effects of magnetic field direction and electrolyte concentration on the microstructure of glass in ECDM, and the effects of machining voltage, field orientation, and electrolyte concentration on the machining performance. Liu et al [10] established the theoretical model of Micromachines 2021, 12, 125.

Results

Discussion

Conclusion