Characterization of Electric Discharge Machining for Silicon Carbide Single Crystal

2008 ◽  
Vol 600-603 ◽  
pp. 855-858 ◽  
Author(s):  
Tomohisa Kato ◽  
Toshiya Noro ◽  
Hideaki Takahashi ◽  
Satarou Yamaguchi ◽  
Kazuo Arai
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electric Discharge ◽  
High Voltage ◽  
High Speed ◽  
Surface Damage ◽  
Lower Surface ◽  
Etch Pits ◽  
Electric Discharge Machining

In this study, we report electric discharge machining (EDM) as a new cutting method for silicon carbide (SiC) single crystals. Moreover, we discuss characteristics and usefulness of the EDM for the SiC. The EDM realized not only high speed and smooth cutting but also lower surface damage. Defect propagation in the EDM SiCs have been also estimated by etch pits observation using molten KOH, however, we confirmed the EDM has caused no damage inside the SiCs in spite of high voltage and high temperature during the machining.

Electric Discharge Machining for Silicon Carbide and Related Materials

2008 ◽  
Vol 600-603 ◽  
pp. 851-854 ◽  
Author(s):  
Satarou Yamaguchi ◽  
Toshiya Noro ◽  
Hideaki Takahashi ◽  
Hideyoshi Majima ◽  
Yoshihisa Nagao ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electric Discharge ◽  
Electric Field Effect ◽  
Electric Discharge Machining ◽  
Avalanche Effect ◽  
Cutting Surface ◽  
Cutting Rate ◽  
Diamond Saw ◽  
High Temperature Effect

In order to cut the ingots and slabs of the silicon carbide (SiC), we developed the new method of electric discharge machining (EDM). EDM is usually used for the machining of the metals, and if it is electric conductive material, it is effective for the machining. However, if the electrical resistivity of SiC is high, the electric current cannot be large enough for and the EDM, and we failed the machining of SiC. Therefore, we use three methods to keep higher electric conduction. One is photoconductive, the second is high electric field effect and it is called avalanche effect, and the third is high temperature effect because usually the resistivity is low when the semiconductor or insulation materials are in high temperature. Thus, we applied three method, and finally can cut the SiC slabs of the resistivity of the order of 10 Ωm, which is almost 1000 times higher than that of the ordinary EDM at least. The flatness of the cutting surface is the same of the metals’ and the cutting rate for the SiC ingots is 10 times higher than that of diamond saw. This technique will be effective for the related materials of SiC, such as diamonds and GaN.

Cutting Speed of Electric Discharge Machining for SiC Ingot

2012 ◽  
Vol 717-720 ◽  
pp. 861-864 ◽  
Author(s):  
Hideki Yamada ◽  
Satarou Yamaguchi ◽  
Norimasa Yamamoto ◽  
Tomohisa Kato
Keyword(s):  
Silicon Carbide ◽  
Electric Discharge ◽  
Cutting Speed ◽  
Experimental Results ◽  
New Method ◽  
Electric Discharge Machining ◽  
Hard Materials ◽  
Diameter Ingot ◽  
Diamond Saw

A new method based on electric discharge machining (EDM) was developed for cutting a silicon carbide (SiC) ingot. The EDM method is a very useful technique to cut hard materials like SiC. By cutting with the EDM method, kerf loss and roughness of sample are generally smaller than those obtained by cutting with a diamond saw. Moreover, the warpage is smaller than that by the diamond saw cutting, and the cutting speed can be 10 times faster than that of the diamond saw at the present time. We used wires of 50 mm and 100 mm diameters in the experiments, and the experimental results of the cutting speed and the kerf losses are presented. The kerf loss of the 50 mm wire is less than 100 mm, and the cutting speed is about 0.8 mm/min for the thickness of a 6 mm SiC ingot. If we can maintain the cutting speed, the slicing time of a 2 inches diameter ingot would be about seven hours.

Attritious Wear of Silicon Carbide

1976 ◽  
Vol 98 (4) ◽  
pp. 1125-1134 ◽  
Author(s):  
R. Komanduri ◽  
M. C. Shaw
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
High Temperature ◽  
High Speed ◽  
Layer By Layer ◽  
Wear Area ◽  
Work Material ◽  
Transmission Electron ◽  
Metal Silicides ◽  
Boundary Fracture

Attritious wear of silicon carbide in simulated grinding tests against a cobalt base superalloy at high speed and extremely small feed rate was studied using a scanning electron microscope (SEM) and an auger electron spectroscope (AES). In many cases the wear area of silicon carbide was found to be concave rather than planar in shape. Several microcracks and grain boundary fracture were also observed. No evidence of metal build-up was observed on silicon carbide which was not the case with aluminum oxide. AES study of the rubbed surface on the work material and transmission electron microscope (TEM) investigation of the wear debris suggest that attritious wear of silicon carbide is due to one or more of the following mechanisms: 1 – Preferential removal of surface atoms on the abrasive, layer by layer, by oxidation under high temperature and a favorably directed shear stress; 2 – disassociation of silicon carbide at high temperature and (a) diffusion of silicon into the work material and formation of metal silicides and (b) diffusion of carbon into the work material and formation of unstable metal carbides (in the present case Ni3C and Co3C) which decompose during cooling to metal and carbon atoms; 3 – pinocoidal cleavage fracture of silicon carbide on basal planes c(0001) resulting in the removal of many micron-sized crystallites.

High-temperature modeling and characterization of 6H silicon carbide metal-oxide-semiconductor field-effect transistors

2005 ◽  
Vol 97 (4) ◽  
pp. 046106 ◽  
Author(s):  
Stephen K. Powell ◽  
Neil Goldsman ◽  
Aivars Lelis ◽  
James M. McGarrity ◽  
Flynn B. McLean
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Metal Oxide ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Temperature Modeling

scholarly journals Analysis of Surface Microgeometry Created by Electric Discharge Machining

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3830
Author(s):  
Tomasz Bartkowiak ◽  
Michał Mendak ◽  
Krzysztof Mrozek ◽  
Michał Wieczorowski
Keyword(s):  
Curvature Tensor ◽  
Electric Discharge ◽  
Surface Characterization ◽  
Tensor Analysis ◽  
Principal Curvatures ◽  
Motif Analysis ◽  
Electric Discharge Machining ◽  
Surface Microgeometry ◽  
Focus Variation

The objective of this work is to study the geometric properties of surface topographies of hot-work tool steel created by electric discharge machining (EDM) using motif and multiscale analysis. The richness of these analyses is tested through calculating the strengths of the correlations between discharge energies and resulting surface characterization parameters, focusing on the most representative surface features—craters, and how they change with scale. Surfaces were created by EDM using estimated energies from 150 to 9468 µJ and measured by focus variation microscope. The measured topographies consist of overlapping microcraters, of which the geometry was characterized using three different analysis: conventional with ISO parameters, and motif and multiscale curvature tensor analysis. Motif analysis uses watershed segmentation which allows extraction and geometrically characterization of each crater. Curvature tensor analysis focuses on the characterization of principal curvatures and their function and their evolution with scale. Strong correlations (R2 > 0.9) were observed between craters height, diameter, area and curvature using linear and logarithmic regressions. Conventional areal parameter related to heights dispersion were found to correlate stronger using logarithmic regression. Geometric characterization of process-specific topographic formations is considered to be a natural and intuitive way of analyzing the complexity of studied surfaces. The presented approach allows extraction of information directly relating to the shape and size of topographic features of interest. In the tested conditions, the surface finish is mostly affected and potentially controlled by discharge energy at larger scales which is associated with sizes of fabricated craters.

Research of Anticorrosion in Desulfurization Flue

2011 ◽  
Vol 301-303 ◽  
pp. 462-466
Author(s):  
Hong Zhu
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Electric Discharge ◽  
Flue Gas ◽  
Flue Gas Desulfurization ◽  
Pass Rate ◽  
Electric Discharge Machining ◽  
Technical Parameters ◽  
Design Life ◽  
Design Requirements

Anti-corrosion coating in desulphurization flue of one wet flue gas desulfurization equipment (FGD) (model 1 and model 2) was designed and studied according to environmental and technical parameters of a coal-fired power plant. And relevant design requirements were confirmed. Application results showed that polyureas has wear and high temperature physical properties, so that it can be used in flue desulfurization equipment for anticorrosion. When the construction of a thickness of 2.0 mm, the high-temperature polyureas protective coating appearance smooth, EDM(electric discharge machining) 100% pass rate, adhesion 10.8 MPa, at 160 °C environment still had outstanding performance, that make sure it could reach its design life of the flue based on estimating the corrosion margin.

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.

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