Experimental Investigation of Copper-Tungsten Electrode Wear in EDM

2014 ◽  
Vol 1017 ◽  
pp. 818-824
Author(s):  
Jian Wu Yu ◽  
Li Hua He ◽  
Xiao Min Sheng ◽  
Wen Duan ◽  
Shao Hui Yin ◽  
...  

Copper-tungsten alloy which is widely used in the field of EDM has high melting temperature and excellent electrical and thermal conductivity. Copper tungsten electrodes for electrical discharge dressing of metal-bond wheel were studied, and experiments were conducted to observe their wear performance in this paper. Orthogonal experiment was designed to explore the wear at the edge of and the bottom of electrode with the machining of holes. Thickness of the carbon layer, micro topography and experimental results were analyzed. Low current and big pulse duration can reduce the electrode wear rate. Although carbon on the electrode surface can be wiped out easily, wear rate of copper-tungsten electrode decreases with the increasing in thickness of the carbon at the initial phase. There are fewer cracks and residue presented on the machined surface by microscope.

Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.


ROTASI ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 9
Author(s):  
Petrus Londa

Keausan elektroda pada proses EDM die sinking adalah peristiwa yang tidak dapat di hindari, namun dengan mengatur variabel pemotongan yang sesuai, diharapkan keausan yang terjadi se-minim mungkin sehingga dapat menjamin tingkat akurasi ukuran pada benda kerja yang di hasilkan. Pada penelitian ini di pilih metode Taguchi untuk menentukan variabel pemotongan yang optimum pada elektroda tembaga dan benda kerja dari bahan K460 (amutit S). Taguchi L9 orthogonal array, signal-to-noise ratio (S/N ratio) dan analysis of variance (ANOVA) dapat menentukan performa variabel proses EDM (PON, POFF, QDON dan GAP) dengan parameter yang di teliti adalah Electrode Wear Rate (EWR) dan Material Removal Rate (MRR). Hasil dari eksperimen tersebut di tampilkan dalam bentuk tabel-tabel dan grafik


2010 ◽  
Vol 154-155 ◽  
pp. 794-805 ◽  
Author(s):  
Yao Jang Lin ◽  
Yan Cherng Lin ◽  
A Cheng Wang ◽  
Der An Wang ◽  
Han Ming Chow

This study investigates the feasibility of EDM for processing ZrO2 and Al2O3 of non-conductive ceramics, which were covered by an assisted conductive material, an adherent copper foil, on the workpiece surface. The conductive material adhered on the surface of the non-conductive ceramics would induce a series of electrical discharges between the tool electrode and the workpiece in the initial stage of the EDM process. Thus, the pyrolytic carbon that cracked from kerosene was formed and deposited on the machined surface to maintain the progress of EDM. In this work, the essential EDM machining parameters were varied to determine the effects on material removal rate (MRR), electrode wear rate (EWR), and surface roughness. The stability of EDM progress and the surface integrities of ZrO2 and Al2O3 machined by EDM were also investigated. The aim of this study is to explore the feasibility and development of an applicable process for processing non-conductive ceramics through EDM. Moreover, the exploitation of this work can be applied to industrial applications and used to develop machining techniques for non-conductive ceramics.


Author(s):  
Santosh Kumar Sahu ◽  
Saurav Datta

Inconel 718 is a nickel-based super alloy widely applied in aerospace, automotive, and defense industries. Low thermal conductivity, extreme high temperature strength, strong work-hardening tendency make the alloy difficult-to-cut. In contrast to traditional machining, nonconventional route like electro-discharge machining is relatively more advantageous to machine this alloy. However, low thermal conductivity of Inconel 718 restricts electro-discharge machining from performing well. In order to improve the electro-discharge machining performance of Inconel 718, powder-mixed electro-discharge machining was reported in this paper. It was carried out by adding graphite powder to the dielectric media in consideration with varied peak discharge current. The morphology and topographical features of the machined surface including surface roughness, crack density, white layer thickness, metallurgical aspects (phase transformation, crystallite size, microstrain, and dislocation density), material migration, residual stress, microindentation hardness, etc. were studied and compared with that of the conventional electro-discharge machining. Additionally, effects of peak discharge current were discussed on influencing different performance measures of powder-mixed electro-discharge machining. Material removal efficiency and tool wear rate were also examined. Use of graphite powder-mixed electro-discharge machining was found to be better in performance for improved material removal rate, superior surface finish, reduced tool wear rate, and reduced intensity as well as severity of surface cracking. Lesser extent of carbon migration onto the machined surface as observed in powder-mixed electro-discharge machining in turn reduced the formation of hard carbide layers. As compared to the conventional electro-discharge machining, graphite powder-mixed electro-discharge machining exhibited relatively less microhardness and residual stress at the machined surface.


2014 ◽  
Vol 543-547 ◽  
pp. 3750-3753
Author(s):  
Shu Yang Liu ◽  
Zhi Hong Han

Based on the analysis of the sputtering power of field-emission electrons which hit on the end surface of positive electrode, the wear mechanism of electrode materials was studied during positive EDM process The theoretical prediction equations of maximum and minimum electrode wear rate were deduced respectively in this paper.


2008 ◽  
Vol 53-54 ◽  
pp. 243-247 ◽  
Author(s):  
Bo Zhao ◽  
Ming Li Zhao ◽  
Guo Fu Gao

The influence of ultrasonic vibration on the surface roughness and micro-topography of ceramics plate is discussed in this paper. Grinding assisted by two-dimensional ultrasonic vibration is developed to deal with the processing difficulty of ceramic materials due to its hard-brittle property. The experimental results show that the surface roughness value obtained in two-dimensional ultrasonic grinding nano-ZrO2 ceramic plate specimen is obviously smaller than that in common grinding, and the scratched grooves on the machined surface in ultrasonic grinding is wider and relatively smoother than that in common grinding. Consequently, it proves that the two-dimensional ultrasonic machining is a feasible, high-efficient machining method for hard-brittle materials.


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