FINE TUNGSTEN FROM W/MGO MECHANOCOMPOSITE OBTAINED BY THE REDUCTION OF TUNGSTEN (VI) OXIDE BY MAGNESIUM

2019 ◽  
Keyword(s):  
Fine Tungsten

Si-targets in fine tungsten gauze

1987 ◽  
Vol 254 (1) ◽  
pp. 210-211 ◽  
Author(s):  
H.J. Kaper ◽  
J. Van Klinken ◽  
T.W. Tuintjer ◽  
V.A. Wichers
Keyword(s):  
Fine Tungsten

Very fine tungsten and molybdenum powders produced by the thermal decomposition of carbonyl vapors

1989 ◽  
Vol 28 (2) ◽  
pp. 80-85
Author(s):  
Yu. K. Kuz'mina ◽  
A. A. Uél'skii ◽  
V. G. Syrkin ◽  
Zh. M. Glukhovskaya ◽  
M. A. Khatsernov
Keyword(s):  
Thermal Decomposition ◽  
Fine Tungsten

EFFECT OF COARSE-TO-FINE WC GRAIN RATIO ON MECHANICAL PROPERTIES AND ABRASIVE WEAR OF WC-8Co CEMENTED CARBIDES

Tribologia ◽  
2016 ◽  
Vol 265 (1) ◽  
pp. 103-115
Author(s):  
Der-Liang YUNG ◽  
Maksim ANTONOV ◽  
Irina HUSSAINOVA ◽  
Renno VEINTHAL ◽  
Sture HOGMARK
Keyword(s):  
Abrasive Wear ◽  
Rupture Strength ◽  
Ultrafine Grain ◽  
Cemented Carbides ◽  
Wear Properties ◽  
Fine Grain ◽  
Material Hardness ◽  
Fine Tungsten ◽  
Grain Distribution ◽  
Coarse To Fine

This study performs a comprehensive analysis concerning the amount of fine tungsten carbide (WC) grains needed for the appropriate reinforcement of the cobalt (Co) metallic binder in WC-8Co cemented carbides. The goal is to investigate the balance of coarse-to-fine grain distribution to achieve overall improvement of the material’s mechanical and wear properties. All samples possessed the same WC-8Co binder content, therefore, allowing the role of grain size distribution to be tested. It was found that a ratio of 8:1 wt% of coarse to ultrafine grain WC yielded an appropriate balance between material hardness, fracture toughness, and rupture strength. Upon adding grain growth inhibitors vanadium carbide (VC) and chromium carbide (Cr3C2), the overall wear resistance is further improved compared to undoped composites when samples are tested under abrasive wear conditions.

Production of Fine Tungsten Powder by Electrolytic Reduction of Solid CaWO4in Molten Salt

2012 ◽  
Vol 159 (6) ◽  
pp. E139-E143 ◽  
Author(s):  
Dingding Tang ◽  
Wei Xiao ◽  
Huayi Yin ◽  
Longfei Tian ◽  
Dihua Wang
Keyword(s):  
Molten Salt ◽  
Tungsten Powder ◽  
Electrolytic Reduction ◽  
Fine Tungsten

Liquid-phase sintering of very fine tungsten-copper powder mixtures

1982 ◽  
Vol 21 (6) ◽  
pp. 447-450 ◽  
Author(s):  
V. V. Panichkina ◽  
M. M. Sirotyuk ◽  
V. V. Skorokhod
Keyword(s):  
Liquid Phase ◽  
Copper Powder ◽  
Liquid Phase Sintering ◽  
Powder Mixtures ◽  
Fine Tungsten

Generation of a Two-Dimensional Silicon Carbide Lattice*

1965 ◽  
Vol 9 ◽  
pp. 142-151 ◽  
Author(s):  
R. L. Prickett ◽  
R. L. Hough
Keyword(s):  
Silicon Carbide ◽  
Vertical Integration ◽  
Tungsten Wire ◽  
Pyrolysis Temperature ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Organic Vapors ◽  
X Ray ◽  
Fine Tungsten

AbstractSilicon carbide vvas generated by pyrolysis of gas mixtures consisting of silicon tetrachloride, hydrogen, and organic vapors, such as acetone, on fine tungsten wires resistance-heated at 1500°C. Prominent two-dimensional structure was demonstrated for the 220 reflection. All other lines were of the normal threedimensional lattice type.Elevation of less than 100° in the pyrolysis temperature eliminated the twodimensional reflection, and simultaneously changed the visible crystallite size.Specialized techniques were used td generate the silicon carbide deposits and also to examine the structure of these deposits by X-ray diffraction to obtain lines from only the silicon carbide while ignoring the tungsten wire core. Diffraction techniques include offset collimation and vertical integration.

Influence of substrate on retraction of neurites following electrical activity of leech Retzius cells in culture

1992 ◽  
Vol 167 (1) ◽  
pp. 1-14
Author(s):  
S. Grumbacher-Reinert ◽  
J. Nicholls
Keyword(s):  
Electrical Stimulation ◽  
Neurite Outgrowth ◽  
Concanavalin A ◽  
Short Delay ◽  
Neurite Retraction ◽  
Promote Neurite Outgrowth ◽  
Tungsten Microelectrode ◽  
Fine Tungsten ◽  
Influence Of Substrate ◽  
Retzius Cells

1. The aim of these experiments was to determine how electrical stimulation of identified neurones in culture influences their growth on defined substrates. Single Retzius cells isolated from the central nervous system (CNS) of the leech were plated in culture dishes coated with the plant lectin Concanavalin A or with extracellular matrix extract containing leech laminin to promote neurite outgrowth. Stimuli were applied by a fine tungsten microelectrode placed close to the cell surface. The efficacy of electrical stimulation was checked occasionally by recording intracellularly with a microelectrode. 2. After the period of stimulation had ended, there was a short delay before neurones plated on leech laminin retracted their neurites. Of 112 neurones, only 11 failed to respond to stimulation. Neurite retraction in each cell was non-uniform, some processes retracting while others did not. After having retracted, most neurites subsequently showed clear regrowth. The degree of retraction depended on the duration of the stimulus train: whereas a few minutes was sufficient to produce observable effects, prolonged periods of stimulation caused more extensive retraction. Trains of impulses at 4 s-1 were equally effective when they were delivered in intermittent bursts or continuously. 3. The time in relation to growth at which stimuli were applied was of critical importance. Neurones stimulated during the phase of rapid outgrowth on leech laminin did not retract their neurites, which continued to elongate during and after stimulation. Neurones that had not retracted during the early phase were stimulated again later, when extension and outgrowth of neurites had ceased or slowed. At this stage stimulation was followed by retraction and subsequent regrowth. 4. Retzius cells plated on a substrate of Concanavalin A instead of leech laminin failed to show any retraction after stimulation. 5. To investigate the possible role of Ca2+, cells were grown with raised concentrations of Mg2+ in the bathing fluid. Raised [Mg2+] did not influence the rate or the extent of neurite outgrowth. It reduced, but did not block, the effects of electrical stimulation. Earlier experiments have shown that growth on Concanavalin A occurs without obvious Ca2+ entry following stimulation. Together with the present experiments, the results suggest that Ca2+ entry following impulses in cells grown on laminin is responsible for the massive retraction.

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