Electrical Discharge Machining with SiC Powder-Mixed Dielectric: An Effective Application in the Machining Process of Hardened 90CrSi Steel

Thi-Hong Tran,Thi-Tam Do,Anh-Tung Luu,Manh-Cuong Nguyen,Thu-Quy Le,Ngoc-Pi Vu,Ngoc-Giang Tran,The-Vinh Do,Trung-Tuyen Vu

doi:10.3390/machines8030036

Abstract

As a successful solution applied to electrical discharge machining (EDM), powder-mixed electrical discharge machining (PMEDM) has been proposed as an upgrade of the EDM process. The optimization of the process parameters of PMEDM is essential and pressing. In this study, Taguchi methods and analysis of variance (ANOVA) were used to find the main parameters affecting surface roughness in the EDM process with SiC powder-mixed-dielectric of hardened 90CrSi steel. The PMEDM parameters selected were the powder concentration, the pulse-on-time, the pulse-off-time, the pulse current, and the server voltage. It was found that SiC powder exhibits positive effects on reducing surface roughness. The roughness obtained with the optimum powder concentration of 4 g/L was reduced by 30.02% compared to that when processed by conventional EDM. Furthermore, the pulse-off-time was found to be the most influential factor that gave an important effect on surface roughness followed by the powder concentration. The EDM condition including a powder concentration of 4 g/L, a pulse-on-time of 6 µs, a pulse-off-time of 21 µs, a pulse current of 8 A, and a server voltage of 4 V resulted in the best surface roughness.

Highlights

Mechanical parts with complex shapes and difficult-to-machine materials are always challenging with traditional machining methods
One of the purposes of this study is to demonstrate the effectiveness of the powder-mixed electrical discharge machining (PMEDM) method compared to traditional electrical discharge machining (EDM)
Results and TableDiscussions indicates the results of the PMEDM process and signal to noise (S/N) ratio

Summary

Introduction

Mechanical parts with complex shapes and difficult-to-machine materials are always challenging with traditional machining methods. As one of the most common non-traditional machining processes, EDM is capable of removing materials by a short-time electrical discharge of high current density between the electrode and the workpiece [3,4,5]. The ability of EDM, is limited by the low material removal rate (MRR), high surface roughness, and high obstacles, PMEDM has been introduced as an advanced method to enhance the capabilities of EDM. The effect the concentration of SiC the authors concluded that thecurrent concentration of SiC particle was theof most influential factor for powder particle on MRR and the tool wear rate in micro-electrical discharge machining of Ti-6Al-4V was investigated by Kuriachen and Mathew [20]. In another study [21], Razak found that applying SiC powder mixed electrical discharge machining reduced roughness, increased MRR, and reduced production time and costs.

Experimental Design

Results and Discussions

TrialAverage

Conclusions

Methods