A New Measurement Method of Relative Volume Wear Ratio Based on Discharge Debris Composition Analysis in Micro-EDM

Wei Liu,Xinyi Zheng,Shangbo Zou,Zhenyuan Jia

doi:10.1155/2014/479609

Abstract

In microelectrical discharge machining (micro-EDM) milling process, due to the unavoidability of electrode wear, selection of electrode with high electrical erosion resistance and accurate electrode compensation is entitled to be conducted to ensure high precision and high quality. The RVWR is used as criterion for electrode wear characteristics and is fundamental to achieve accurate electrode compensation; however, it is hardly measured accurately with conventional methods. In this paper, firstly, the error of RVWR measured by conventional measurement method is analyzed. Thereafter, for accurately measuring RVWR, a new measurement method is proposed based on electrical debris composition analysis. The RVWR of widely used tungsten, molybdenum, and copper electrode in machining different materials is measured, respectively, and the optimum electrode is selected based on the measuring results. Finally, microgrooves on different materials are machined with tungsten electrode, and the experiment results show that the microstructures have good bottom surface profiles, which indicates that the proposed method is effective to precisely measure the RVWR and guarantee accurate electrode compensation in micro-EDM process.

Highlights

With the continuous development of technologies in various industrial fields quite recently, the demands on product miniaturization are getting increasingly intensive, which stimulates the innovation on new micromachining and precision machining approaches with high machining efficiency and quality
In micro-EDM milling process, in order to avoid frequent compensation and achieve better size and shape accuracy, it is desirable that the electrode with high electrical erosion resistance can be employed effectively, which means that the machined distance L should be as
Based on electrical debris composition analysis, a new relative volume wear ratio (RVWR) measurement method is proposed, which can be applicable to different electrodes machining different workpiece materials without simplifying the processing environment

Summary

Introduction

With the continuous development of technologies in various industrial fields quite recently, the demands on product miniaturization are getting increasingly intensive, which stimulates the innovation on new micromachining and precision machining approaches with high machining efficiency and quality. Microelectrical discharge machining (microEDM), because of such advantages as contact-less process, no cutting force, low cost, and wide materials suit to fabricate, has been widely applied in the manufacturing of geometrically complex and hard material microstructures. At present, it has been recognized as one of the most valuable techniques for micromachining [1,2,3]. Owing to the principle of EDM, the occurrence of electrode wear is inevitable It is much more severe in micro-EDM milling process, due to certain characters of micro-EDM, such as microenergy and high frequency discharge, microsized electrode, large depth-towidth ratio, and hostile processing condition. In order to enhance machining precision and quality, accurate and effective electrode compensation is entitled to be conducted in micro-EDM milling processes

Methods

Results

Conclusion