Experimental Study on Electrode Wear of Diamond-Nickel Coated Electrode in EDM Small Hole Machining

Yu Liu,Shengfang Zhang,Wenchao Zhang,Dapeng Yang,Zhihua Sha,Fujian Ma,Wenjian Wang

doi:10.1155/2019/7181237

Yu Liu, Shengfang Zhang + Show 5 more

Open Access

https://doi.org/10.1155/2019/7181237

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Abstract

Aiming at the problem of obvious tool length wear and side wear in the small hole processing of EDM, the nickel-coated composite electrode and diamond-nickel-coated composite electrode were prepared by chemical composite coating using brass, copper, molybdenum, and copper-tungsten alloy materials as the matrix material. Comparative experiments of EDM small hole machining using composite tools were carried out on die steel. The effects of nickel-coated composite electrode and diamond-nickel-coated composite electrode on tool length wear, tool side wear, and tool shape change were analyzed. The results show that the diamond-nickel-coated composite electrode can effectively reduce both the length wear and side wear of the electrodes.

Highlights

Electrical discharge machining (EDM) is a nontraditional machining method, and its material removal principle is to melt and vaporize a small amount of metal by the instantaneous high temperature generated during pulsed electric discharge
In order to prevent tool loss, Hai-Liang and Cao proposed a method of processing small hole machining by EDM using dispersant dielectric fluid. e results showed that the reasonable choice of the composite tool and dispersant dielectric fluid could effectively improve the processing speed, lower tool wear, and improve depth-todiameter ratio of the drilling hole significantly [9]
In order to reduce the significant problem of tool length wear and side wear in EDM, tools of the nickel layer and diamond-nickel layer based on brass, copper, molybdenum, and copper-tungsten alloy materials as the matrix material were made by chemical composite coating

Summary

Introduction

Electrical discharge machining (EDM) is a nontraditional machining method, and its material removal principle is to melt and vaporize a small amount of metal by the instantaneous high temperature generated during pulsed electric discharge. Tsai et al proposed a new method of blending the copper powders containing resin with chromium powders to form tools Such tools are made at low pressure (20 MPa) and temperature (200°C) in a hot mounting machine. Lv prepared a new copper-based nickeltungsten alloy composite tool by the nickel-tungsten codeposition electroplating method and carried out microhole machining experiments. E results showed that the nickeltungsten alloy coating has good erosion resistance performance, which can effectively reduce the side wear of the tool, especially at the end and edge, maintaining the shape of the tool and improving the shape precision of the machined microhole [12]. In order to reduce the significant problem of tool length wear and side wear in EDM, tools of the nickel layer and diamond-nickel layer based on brass, copper, molybdenum, and copper-tungsten alloy materials as the matrix material were made by chemical composite coating. It provides a new tool preparation method for EDM, and the research results have certain guiding significance for the actual production in EDM

Principle of EDM with Composite Tool

Composite Tool Preparation and Experimental Design

Main components of coating solution: nickel sulfate and diamond

Conclusions