Thermally induced defects in a polycrystalline diamond layer on a tungsten carbide substrate

2009 ◽  
Vol 404 (22) ◽  
pp. 4485-4488 ◽  
Author(s):  
B.N. Masina ◽  
A. Forbes ◽  
O.M. Ndwandwe ◽  
G. Hearne ◽  
B.W. Mwakikunga ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Polycrystalline Diamond ◽  
Thermally Induced ◽  
Diamond Layer ◽  
Induced Defects

Formation of Thermally Induced Defects in Silica Optical Material

2013 ◽  
Vol 853 ◽  
pp. 62-67
Author(s):  
Zhong Yin Xiao ◽  
Jian Xiang Wen ◽  
Wen Yun Luo ◽  
Wen Kai Wu ◽  
Ren Xiang Gong ◽  
...  
Keyword(s):  
High Temperature ◽  
Formation Process ◽  
Thermal History ◽  
Defect Formation ◽  
Annealing Process ◽  
Optical Material ◽  
Thermally Induced ◽  
Silica Material ◽  
Heating Treatment ◽  
Induced Defects

Characteristics of silica optical material largely depend on its thermal history. In this paper, formation of thermally induced defects in silica optical material is studied. The formation process of defect is analyzed in detail. The results show that there is an obvious difference in defect formation induced by heating treatment when the composition of silica optical material changes. Defect formation mainly displays as the produce process when the initial defects of the silica material are zero. However, defect formation expresses as the produce and annealing process when the initial defects of the silica material are not zero. The initial defect concentration can be decreased significantly when the silica material is heated in high temperature. At the same time, the new defect is also produced. These theoretic results are consistent with the previous experimental ones.

Thermally Induced Defects on WSe2

2020 ◽  
Vol 124 (28) ◽  
pp. 15337-15346 ◽  
Author(s):  
William H. Blades ◽  
Nicholas J. Frady ◽  
Peter M. Litwin ◽  
Stephen J. McDonnell ◽  
Petra Reinke
Keyword(s):  
Thermally Induced ◽  
Induced Defects

Design of High-Efficient Bits for Igneous Rock in Xushen Gasfield

2013 ◽  
Vol 385-386 ◽  
pp. 308-311
Author(s):  
Li Gang Zhang ◽  
Tie Yan ◽  
Shi Bin Li
Keyword(s):  
Tungsten Carbide ◽  
Design Method ◽  
Polycrystalline Diamond ◽  
High Hardness ◽  
Rake Angle ◽  
Gas Field ◽  
Working Face ◽  
High Efficient ◽  
Low Efficiency ◽  
Bit Life

The igneous rocks in deep formations of the Xushen gasfield have the following characters: high abrasive property, high hardness, and high drillability, which lead to many drill bit accidents, few footage per bit , low efficiency of drilling, long drilling cycle, these severely restrict the exploration and development process of gas field. According to the features of deep formation, a hybird cutters bit is designed. It has three cones, with the overhang cone , duplicate taper and offset cone characters. The tungsten carbide cutters and the polycrystalline diamond compacts cutters are alternative collocation in the same tooth row in the bit. The exposed height of the tungsten carbide cutters is higher than polycrystalline diamond compacts cutters. The back rake angle of polycrystalline diamond compacts cutters is 10 ~ 40 °, the side rake angle is 10 ~ 30 °. The normal direction of working face stay the same with the composite slip direction, and the side rake pointed at adjacent gullet. Through the design method, it is integrated that the advantages of roller bit and PDC bit, the way of impact breakage and rotational shear breakage and the prominent performance of tungsten carbide cutters and polycrystalline diamond compacts cutters. It can improveROP and bit life.

Forming Fine V-Grooves on a Tungsten Carbide Workpiece with a PCD Electrode by EDM

2007 ◽  
Vol 329 ◽  
pp. 631-636 ◽  
Author(s):  
Sadao Sano ◽  
Kiyoshi Suzuki ◽  
Wei Li Pan ◽  
Manabu Iwai ◽  
Yoshihiko Murakami ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Pulse Duration ◽  
Flat Surface ◽  
Short Pulse ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Chemical Vapor Deposition Diamond ◽  
Electrically Conductive ◽  
Short Pulse Duration ◽  
Low Wear

Polycrystalline diamond (PCD) exhibits a thermal conductivity similar to that of the electrically conductive chemical vapor deposition diamond (EC-CVD diamond) found to function as zero-wear electrodes at short pulse duration. In this study, PCD was used as electrodes applied to EDM on tungsten carbide. Two kinds of PCD (CTB-010 and CTH-025) with a flat surface were used. The wear of the PCD electrodes was about 1.5% for very short pulse duration such as te=1μs, but it was zero wear at te=30μs, though the wear of a Cu-W electrode was 10% even on the machine recommended conditions for the low wear. EDM experiment using a V-shaped PCD electrode with an included angle of 45° was also carried out and the performance was compared with the case using a V-shaped Cu-W electrode. Under the conditions of a no load voltage of 60V, a set peak current of 2A, and a medium pulse duration of te=15μs, there was no wear on PCD electrodes when observed under the SEM, whereas a 50μm-deep wear on the Cu-W electrodes even under the machine recommended condition for the low wear was observed.

Polycrystalline Diamond Films as Protection of Zircaloy Fuel Cladding

2014 ◽  
Author(s):  
Jan Škarohlíd ◽  
Radek Škoda
Keyword(s):  
High Temperature ◽  
Ion Beam ◽  
Cooling Water ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Zirconium Alloys ◽  
Carbon Layer ◽  
Primary Circuit ◽  
Temperature Oxidation ◽  
Diamond Layer

Polycrystalline diamond coating is a promising possibility for prevention, or reduction of high temperature oxidation of zirconium alloys. Zirconium alloys are used as cladding material in almost all types of nuclear reactors, where creates a barrier between nuclear fuel and cooling water in the primary circuit. Hydrogen and considerable amount of heat is released during steam oxidation that may occur in an eventual accident. In this paper Zircaloy-2 alloy was covered by polycrystalline diamond layer using Plasma Enhanced Linear Antennas Microwave Chemical Vapor Deposition system reactor. X-Ray Diffraction and Raman spectroscopy measurements confirmed coverage of the surface area with crystalline and amorphous carbon layer. Characterizations were done for zirconium alloy covered with diamond layer before and after corrosion and irradiation tests - ion beam irradiation tests and high temperature steam exposure.

Influence of Tungsten-Carbide and Cobalt on Tool Wear in Cutting of Cemented Carbides with Polycrystalline Diamond Tool

2013 ◽  
Vol 7 (4) ◽  
pp. 433-438 ◽  
Author(s):  
Junsuke Fujiwara ◽  
◽  
Keisuke Wakao ◽  
Takeshi Miyamoto ◽  
Keyword(s):  
Particle Size ◽  
Tool Wear ◽  
Tungsten Carbide ◽  
Diamond Tool ◽  
Polycrystalline Diamond ◽  
Cemented Carbides ◽  
Large Particles

The influence of the tungsten-carbide (WC) particle size and Co contents of cemented carbides on polycrystalline diamond tool wear during turning was investigated experimentally. The main results obtained were as follows. (1) Tool wear increased with increasing Co content. (2) It is important to cut off the binder between the WC particles and the Co. (3) Cemented carbides containing small WC particles are more effective than cemented carbides containing large particles.

Precision Cutting of Structured Ceramic Molds with Micro PCD Milling Tool

2011 ◽  
Vol 5 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Hirofumi Suzuki ◽  
◽  
Tatsuya Furuki ◽  
Mutsumi Okada ◽  
Katsuji Fujii ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Tungsten Carbide ◽  
Polycrystalline Diamond ◽  
Micro Milling ◽  
Grinding Wheels ◽  
Form Accuracy ◽  
Structured Surfaces ◽  
Milling Tool ◽  
Milling Tools

Micro milling tools made of PolyCrystalline Diamond (PCD) have been developed to machine ceramic micro dies and molds. Cutting edges are ground with diamond wheels. PCD milling tool wear is evaluated by cutting binder-less tungsten carbide spherical molds and machining structured surfaces for trial. Results of experiments clarified that PCD milling tool life is over 10 times that of resinoid diamond grinding wheels, and that form accuracy was 0.1 µm-0.3 µm P-V and surface roughness was 10 nm Rz.

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