Study of surface integrity using the small area EDM process with a copper–tungsten electrode

Lee, Hwa-Teng; Hsu, Fu-Chuan; Tai, Tzu Yao

doi:10.1016/j.msea.2003.08.046

Cited by 119 publications

(54 citation statements)

References 23 publications

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“…Four layers are observed after EDM machining. The first one is a debris layer, the second is the white layer, the third one is an annealed layer or heat affected zone and on the final layer parent material can be observed [9,18]. The formation of white layer and its thickness is dependent on both the electrical and non-electrical EDM parameter [13].…”

Section: Introductionmentioning

confidence: 99%

EDM of Aluminum Alloy 6061 Using Graphite Electrode Using Paraffin Oil and Distilled Water as Dielectric Medium

Imran¹,

Rahmanshah²,

Mehmood³

et al. 2017

Adv. Sci. Technol. Res. J.

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EDM machining of Al 6061 was performed under varying conditions of pulse current and pulse duration. Graphite was used as an electrode material with distilled water and paraffin oil as two different dielectric mediums. The aim is to characterize the surface integrity produced as a result of EDM machining under both varying electrical and non-electrical parameters as it is important in determining the service life of EDM machined components. The vertical, horizontal and corner surfaces are studied independently for each single set of conditions. The average white layer thickness (AWLT) and surface roughness was found to be dependent on pulse current values and pulse duration. The dielectric medium also has an influence on the thickness and nature of white layer. It was found that the thickness and nature of the white layer formed from distilled water is different from that of paraffin oil. New methods of AWLT and surface roughness measurement through an optical microscope are described. The surface roughness method developed was calibrated against an identical surface roughness tester. Finally, material removal rate, tool wear rate, the presence of micro cracks, voids and globules were compared for different conditions and conclusions were drawn according to the actual physical conditions during machining.

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Section: Introductionmentioning

confidence: 99%

EDM of Aluminum Alloy 6061 Using Graphite Electrode Using Paraffin Oil and Distilled Water as Dielectric Medium

Imran¹,

Rahmanshah²,

Mehmood³

et al. 2017

Adv. Sci. Technol. Res. J.

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“…In order to obtain surface integrity of Ti-6Al-4V, graphite, electrolytic copper, aluminium and copper-tungsten material were researched as EDM electrodes [11][12][13][14]. EDM dielectric-water-in-oil, kerosene and deionized water were studied to get high MRR and low EWR [15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Experimental study on green electrical discharge machining in tap water of Ti–6Al–4V and parameters optimization

Tang

2013

Int J Adv Manuf Technol

101

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Ti-6Al-4V is widely used in the aerospace, automobile, and biomedical fields, but is a difficult-to-machine material. Electrical discharge machining (EDM) is regarded as one of the most effective approaches to machining Ti-6Al-4V alloy, since it is a non-contact electro-thermal machining method, and it is independent from the mechanical properties of the processed material. This paper aims to combine grey relational analysis and Taguchi methods to solve the problem of EDM parameters optimization. From the viewpoint of health and environment, tap water as working fluid has good working environment, since it does not release harmful gas. The process parameters include discharge current, gap voltage, lifting height, negative polarity and pulse duty factor. The electrode wear ratio (EWR), material removal rate (MRR) and surface roughness (SR) as objective parameters are chosen to evaluate the whole machining effects. Experiments were carried out based on Taguchi L 9 orthogonal array and grey relational analysis, and then verified the results through a confirmation experiment. Compared the machining parameters A 1 B 1 C 3 D 2 with A 1 B 2 C 2 D 2 , MRR increased from 1.28 mm 3 /min to 2.38 mm 3 /min, EWR decreased from 0.14 to 0.10 mm 3 /min and SR decreased from Ra 2.37 μm to Ra 1.93 μm. The process parameters sequenced in order of relative importance are: the ratio of pulse width to pulse interval, discharge current, lifting height and gap voltage. The results showed that using tap water machining Ti-6Al-4V material can obtain high MRR, decrease the machining cost and have no harmful to the operators and the environment.

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“…[5] The formation of surface cracks was attributed to the differentials of high contraction stresses exceeding the material's ultimate tensile strength within the recast layer. [6] Thermal stress is produced when the discharges bombard the surface during the machining process. Tensile stress within the machined surface is generated, because not all of the material melted during discharging is swept away from the surface by the dielectric.…”

Section: Introductionmentioning

confidence: 99%

White Layer Composition, Heat Treatment, and Crack Formation in Electric Discharge Machining Process

Ekmekçi

2009

Metall Mater Trans B

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BÜ LENT EKMEKCICharacteristics of electric discharge machined (EDM) surfaces of normalized, quenched, and quenched and tempered-treated steels in kerosene and deionized-water dielectric liquids are investigated. Optical microscopy, scanning electron microscopy (SEM) and X-ray diffractometry are employed to analyze the machined surface. Surface cracks are examined in terms of white layer composition, heat treatment of the workpiece material, and operational parameters used, such as average discharge current and pulse-on duration. The present results reveal that base material properties and white layer composition have a distinctive function on crack formation that results in different crack network layouts on the surface and penetration depths in the substrate. Surface cracks, which initiate at the surface, travel down perpendicularly toward the interferential zone, and terminate at this interference, are mainly formed due to an increase in nonhomogeneities of metallurgical phases within the white layer. Such cracks are usually encountered on the surfaces when machining is performed in a hydrocarbon-based dielectric liquid using high pulse-on duration and low average discharge current. On the other hand, penetrating cracks, which penetrate the entire white layer thickness to an extent into the parent material, are mainly formed due to contraction of the recast structure joined to the circumferential edge of a crater rim during solidification. This type of crack is common when machining is performed in deionized water and the work material is brittle. Crack penetration depth is found to be proportional to the used pulse energy, and its path has a tendency to form parallel cracks to the machined surface at decreased pulse-on duration.

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Study of surface integrity using the small area EDM process with a copper–tungsten electrode

Cited by 119 publications

References 23 publications

EDM of Aluminum Alloy 6061 Using Graphite Electrode Using Paraffin Oil and Distilled Water as Dielectric Medium

EDM of Aluminum Alloy 6061 Using Graphite Electrode Using Paraffin Oil and Distilled Water as Dielectric Medium

Experimental study on green electrical discharge machining in tap water of Ti–6Al–4V and parameters optimization

White Layer Composition, Heat Treatment, and Crack Formation in Electric Discharge Machining Process

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