scholarly journals Elemental and Thermochemical Analyses of Materials after Electrical Discharge Machining in Water: Focus on Ni and Zn

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3189
Author(s):  
Sergey N. Grigoriev ◽  
Marina A. Volosova ◽  
Anna A. Okunkova ◽  
Sergey V. Fedorov ◽  
Khaled Hamdy ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
12Kh18n10t Steel ◽  
Water Medium ◽  
Nickel Steel ◽  
Intermetallic Compound Formation ◽  
Electrical Erosion ◽  
Materials Used ◽  
First Time

The mechanism of the material destruction under discharge pulses and material removal mechanism based on the thermochemical nature of the electrical erosion during electrical discharge machining of conductive materials were researched. The experiments were conducted for two structural materials used in the aerospace industry, namely austenite anticorrosion X10CrNiTi18-10 (12kH18N10T) steel and 2024 (D16) duralumin, machined by a brass tool of 0.25 mm in diameter in a deionized water medium. The optimized wire electrical discharge machining factors, measured discharge gaps (recommended offset is 170–175 µm and 195–199 µm, respectively), X-ray photoelectron spectroscopy for both types of materials are reported. Elemental analysis showed the presence of metallic Zn, CuO, iron oxides, chromium oxides, and 58.07% carbides (precipitation and normal atmospheric contamination) for steel and the presence of metallic Zn, CuO, ZnO, aluminum oxide, and 40.37% carbides (contamination) for duralumin. For the first time, calculating the thermochemistry parameters for reactions of Zn(OH)2, ZnO, and NiO formation was produced. The ability of Ni of chrome–nickel steel to interact with Zn of brass electrode was thermochemically proved. The standard enthalpy of the Ni5Zn21 intermetallic compound formation (erosion dust) ΔH0298 is −225.96 kJ/mol; the entropy of the crystalline phase Scint is 424.64 J/(mol·K).

scholarly journals Sub-Microstructure of Surface and Subsurface Layers after Electrical Discharge Machining Structural Materials in Water

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1040
Author(s):  
Sergey N. Grigoriev ◽  
Marina A. Volosova ◽  
Anna A. Okunkova ◽  
Sergey V. Fedorov ◽  
Khaled Hamdy ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Structural Materials ◽  
12Kh18n10t Steel ◽  
Mean Deviation ◽  
Water Medium ◽  
Tool Electrode ◽  
Marquardt Algorithm ◽  
Subsurface Layers ◽  
Electrical Wear

The material removal mechanism, submicrostructure of surface and subsurface layers, nanotransformations occurred in surface and subsurface layers during electrical discharge machining two structural materials such as anti-corrosion X10CrNiTi18-10 (12kH18N10T) steel of austenite class and 2024 (D16) duralumin in a deionized water medium were researched. The machining was conducted using a brass tool of 0.25 mm in diameter. The measured discharge gap is 45–60 µm for X10CrNiTi18-10 (12kH18N10T) steel and 105–120 µm for 2024 (D16) duralumin. Surface roughness parameters are arithmetic mean deviation (Ra) of 4.61 µm, 10-point height (Rz) of 28.73 µm, maximum peak-to-valley height (Rtm) of 29.50 µm, mean spacing between peaks (Sm) of 18.0 µm for steel; Ra of 5.41 µm, Rz of 35.29 µm, Rtm of 43.17 µm, Sm of 30.0 µm for duralumin. The recast layer with adsorbed components of the wire tool electrode and carbides was observed up to the depth of 4–6 µm for steel and 2.5–4 µm for duralumin. The Levenberg–Marquardt algorithm was used to mathematically interpolate the dependence of the interelectrode gap on the electrical resistance of the material. The observed microstructures provide grounding on the nature of electrical wear and nanomodification of the obtained surfaces.

Einsatz eines naturanalogen Algorithmus/Application of a natural analogue algorithm – Reproducible optimization of electrical-discharge drilling

2020 ◽  
Vol 110 (07-08) ◽  
pp. 467-470
Author(s):  
Eckart Uhlmann ◽  
Mitchel Polte ◽  
Jan Streckenbach ◽  
Mirsad Osmanovic ◽  
Julian Börnstein
Keyword(s):  
Industrial Application ◽  
Electrical Discharge ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Optimization Method ◽  
Hardened Steel ◽  
Evolution Strategy ◽  
Natural Analogue ◽  
Electrical Discharge Drilling ◽  
Materials Used

Dieser Beitrag stellt die Ergebnisse zur Untersuchung der Reproduzierbarkeit des Optimierungsverfahrens Evolutionsstrategie (ES) am Beispiel des funkenerosiven Bohrens vor. Dazu wurden zwei ES-Typen untersucht. Als Elektrodenwerkstoffe kamen Messing für das Werkzeug und für das Werkstück gehärteter Stahl zum Einsatz. Im Ergebnis konnte die Erosionsdauer reproduzierbar um 37 % verringert werden. Dieser Nachweis bildet die Grundlage für den industriellen Einsatz der Evolutionsstrategie beim funkenerosiven Bohren.   This article describes the results of the investigation on the reproducibility of the optimization method of evolution strategy (ES), exemplified by electrical-discharge drilling. Two types of ES were examined. The electrode materials used were brass for the tool and hardened steel for the workpiece. The erosion duration could be reduced by 37 % in a reproduceable manner. This verification is the basis for the industrial application of the ES for the optimization of electrical discharge machining.

Effects of Machining Fluid on Electric Discharge Machining of SiC Ingot

2014 ◽  
Vol 778-780 ◽  
pp. 767-770 ◽  
Author(s):  
Norimasa Yamamoto ◽  
Satarou Yamaguchi ◽  
Tomohisa Kato
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Ion Exchange ◽  
Electric Discharge ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electric Discharge Machining ◽  
The Wire ◽  
Characteristic Features ◽  
First Time

Recently, ingots of silicon carbide have been adapted to be sliced by the wire-cut electrical discharge machining. Fast slicing, and the reduction in the loss are important for slicing of the wafer. In this paper, characteristic features of the electric discharge machining in the ion-exchange water and the fluorine-based fluid were compared for these improvement. The discharge was caused by a pulse voltage applied to a ingot of silicon carbide and the wire in machining fluid, and the slicing was proceeded. As a result, improvement of surface roughness and kerf loss was confirmed, for the first time. In addition, the improving methods for fast slicing were considered.

Machining Characteristics of IN718 by EDM with Cooled Electrode and Vibration of the Workpiece

2020 ◽  
Vol 996 ◽  
pp. 131-136
Author(s):  
Yao Li ◽  
Cheng Cui ◽  
Bengang Lin ◽  
Li Li
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Cryogenic Cooling ◽  
Tool Electrode ◽  
Machining Efficiency ◽  
Electrical Erosion ◽  
Machining Characteristics ◽  
Edm Process ◽  
Process Material

Inconel718 has been widely used in various fields for its good performance, but it is difficult to machine with traditional machining methods. Electrical discharge machining is an alternative competitive process to machine Nickel-based alloys by electrical erosion. In order to improve reduce the electrode loss and improve the machining efficiency, the horizontal ultrasonic vibration of the workpiece and the cryogenic cooling of the tool electrode were applied into the EDM process. Material removal efficiency, surface roughness, surface topography, and microhardness have been characterized.

Research on discharge characteristics of working mediums of electric discharge machining

2020 ◽  
Vol 235 (1-2) ◽  
pp. 34-40
Author(s):  
Min Li ◽  
Lanrong Cai ◽  
Junling Zhao
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Base Material ◽  
Deionized Water ◽  
Water Medium ◽  
Discharge Process ◽  
Dry Powder ◽  
Discharge Characteristics ◽  
Mixed Medium ◽  
Tc4 Alloy

Successful surface modification can be obtained by Electrical Discharge Machining (EDM). In this work the discharge characteristics in misted deionized water and near-dry powder-mixed medium was studied systematically, as well as the microstructure and properties of electrical discharge strengthened layers on TC4 alloy. It indicates that the breakdown voltage of EDM in misted deionized water medium has been reduced to about 1/3 than in air medium. In near-dry powder-mixed medium, it is reduced to about 1/9, because the discharge gap is much larger than that of other mediums. In other words, a stable discharge can be obtained by larger discharge gaps and lower pulse energy than traditional EDM surface strengthening method, which leads to more stable discharge process. Experimental researches show that dense and sound combination with matrix like, multiphase hybrid intensification and chrysanthemum petal-like microstructure of strengthened layers can be observed in the near-dry powder-mixed medium. Meanwhile, it is found that the microhardness of the strengthened layer is up to about 1200 HV, which is four times higher than the base material.

Hazard Identification in Electrical Discharge Machining (EDM) Process Using What-If Analysis 

2014 ◽  
Vol 592-594 ◽  
pp. 2508-2512 ◽  
Author(s):  
S.P. Sivapirakasham ◽  
S. Thiyagarajan ◽  
P. Bineesh ◽  
Jose Mathew ◽  
M. Surianarayanan
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Hazard Analysis ◽  
Hazard Identification ◽  
Safety And Health ◽  
Machining System ◽  
Key Techniques ◽  
And Control ◽  
First Time ◽  
Edm Process

This paper provides guidance to key techniques and methods used in the EDM process industry for identifying and documenting environment, safety, and health (ESH) hazards and theircontrols.This is first time that the brainstorming method “what-if” analysis,one of the well-known process hazard analysis (PHA) techniques, is used to predict hazards in electrical discharge machining (EDM) processes. This technique analyzes potential causes and consequences of fires, explosions, releases of toxic or flammable chemicals and major spills of hazardous chemicals, and focuses on fluid system, machining system, electrical & instrumentation system, utilities, human actions and external factors that might impact the process. This analysis helped to identify conditions that can lead to an accident situation and recommendations are givento overcome the risks of these situations. An exhaustive analysis in the EDM process to identify and analyze hazards is presented in this paper and control recommendations are provided to overcome the risks of these hazards.

A Survey on Electrode Materials for Electrical Discharge Machining

2011 ◽  
Vol 697-698 ◽  
pp. 495-499 ◽  
Author(s):  
Li Zhang ◽  
Li Hua Dong ◽  
D.S. Wang ◽  
C.H. Fan ◽  
Y. Zhou
Keyword(s):  
Electrical Discharge ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Industrial Applications ◽  
High Wear Resistance ◽  
Wear Loss ◽  
Melting Points ◽  
Edm Electrodes ◽  
Materials Used ◽  
Shape Loss

This work screens electrode materials used in EDM and proposes some potential electrodes for future industrial applications. Traditional graphite, W, and Mo EDM electrodes have low TWR due to their high melting points; while, Zn, brass, and Cu often experience too much tool wear. As to some newly developed alloy and composite materials, their machining performances depend on not only their melting points but also their microstructures. Cu-W alloy has high wear resistance but it is susceptible to shape loss due to its internal porosity. By contrast, Cu-graphite, Cu-ZrB2 and Cu-TiB2 composites show good capabilities of removing material with little wear loss and therefore could be promising for future usages.

Melting and Evaporation Phenomena During Electrical Erosion

1975 ◽  
Vol 97 (4) ◽  
pp. 576-581 ◽  
Author(s):  
M. Toren ◽  
Y. Zvirin ◽  
Y. Winograd
Keyword(s):  
Heat Source ◽  
Chemical Reactions ◽  
Experimental Technique ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Dielectric Fluid ◽  
Point Heat Source ◽  
Color Intensity ◽  
Electrical Erosion ◽  
Steel Electrodes

A modeling method is presented for the evaluation of the eroded crater during electrical discharge machining. The method is based on the propagation of the melting crater when other effects such as evaporation can take place. Calculations are performed for a point heat source on the surface of copper and steel electrodes. An experimental technique for the measurement of the amount of eroded material is described: the method consists of extraction of the metal from the dielectric fluid by chemical reactions and measurement of the resulting color intensity.

scholarly journals Electrical Discharge Machining of Oxide Nanocomposite: Nanomodification of Surface and Subsurface Layers

2020 ◽  
Vol 4 (3) ◽  
pp. 96
Author(s):  
Sergey N. Grigoriev ◽  
Marina A. Volosova ◽  
Anna A. Okunkova ◽  
Sergey V. Fedorov ◽  
Khaled Hamdy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Subsurface Layer ◽  
Processes And Reactions ◽  
X Ray ◽  
Subsurface Layers ◽  
Scanning Electron ◽  
Hydrocarbon Oil

The work is devoted to the research of the changes that occur in the subsurface layer of the workpiece during electrical discharge machining of conductive nanocomposite based on alumina with the use of a brass tool. The nanocomposite of Al2O3 + 30% of TiC was electroerosively machined in a water and hydrocarbon oil. The process of electrical discharge machining is accompanied by oscillations that were registered by diagnostic means. The obtained surface of the samples was researched by the means of scanning electron microscopy and X-ray photoelectron spectroscopy. The observed surface and subsurface changes provide grounding for the conclusions on the nature of processes and reactions that occur between two electrodes and nanomodification of the obtained surfaces that can be an advantage for a series of applications.

Analysis of Electrical Discharge Machining Using Water as Dielectric and Diverse Electrode Materials

2008 ◽  
Author(s):  
Hugo Medellin ◽  
Aaro´n Flores ◽  
Jorge Morales ◽  
Alonso de la Garza
Keyword(s):  
Electrical Discharge ◽  
Electrode Materials ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Low Carbon Steel ◽  
Electrode Wear ◽  
Low Carbon ◽  
Source Voltage ◽  
Materials Used ◽  
Edm Process

This paper presents an experimental investigation carried out to study the performance of electrical discharge machining (EDM) using water as dielectric. This experimentation was performed using different types of water as dielectric, several electrode materials and two different workpiece materials. The electrode materials used in the experimentation were bronze, brass, copper, aluminium and steel; and the workpiece materials used were ASTM A36 mild (low-carbon) steel and D-2 tool steel. A new desktop size EDM machine to perform the experiments was designed and is presented in this paper. After performing the experimentation, the results have shown that the best EDM performance is achieved with brass and bronze electrodes using a mixture of 75% tap and 25% deionised water as dielectric. The results also indicate that the material removal rate and the electrode wear are proportional to the source voltage used in the EDM process. Finally, a forming die with a complex shape used in a jewellery industry, was manufactured using the EDM system presented in this paper.

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