scholarly journals The effect of particle structure on apparent density of electrolytic copper powder

2001 ◽  
Vol 66 (11-12) ◽  
pp. 923-933 ◽  
Author(s):  
M.G. Pavlovic ◽  
Lj.J. Pavlovic ◽  
E.R. Ivanovic ◽  
V. Radmilovic ◽  
K.I. Popov
Keyword(s):  
Apparent Density ◽  
Copper Powder ◽  
Metallic Copper ◽  
Microstructural Analysis ◽  
Sieve Analysis ◽  
Particle Structure ◽  
Copper Powders ◽  
Electron Microscopy Analysis ◽  
Powder Particles ◽  
The Difference

The quantitative microstructural analysis and the sieve analysis of copper powder as well as the scanning electron microscopy analysis of the copper powders particles were performed. It was found that the structure of the copper powder particles determines the apparent density of copper powder. The powder particles from the same fractions of different powders occupy approximately the same volume, but the structure of metallic copper is very different. This causes the difference in apparent densities of copper powder obtained under different conditions. The more dendritic is the structure of powder particles the smaller is the apparent density of copper powder.

scholarly journals The effect of reversing current deposition on the apparent density of electrolytic copper powder

2002 ◽  
Vol 67 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Konstantin Popov ◽  
Ljubica Pavlovic ◽  
Evica Ivanovic ◽  
Velimir Radmilovic ◽  
Miomir Pavlovic
Keyword(s):  
Apparent Density ◽  
Copper Powder ◽  
Particle Morphology ◽  
Electrolytic Copper ◽  
Current Wave ◽  
Electrolytic Copper Powder ◽  
Copper Powders ◽  
Morphology And Structure ◽  
Powder Particles

The possibility of depositing copper powders with different apparent density by changing the shape of reversing current wave is shown. The morphology and crystallinity of powder particles can be varied considerably by changing shape of the reversing current wave and, hence, the apparent density of powders. The relation of apparent density with particle morphology and structure was illustrated.

Flowability of Electrolytic Copper Powder

2005 ◽  
Vol 494 ◽  
pp. 247-252 ◽  
Author(s):  
M.G. Pavlović ◽  
K.I. Popov ◽  
S.B. Krstić ◽  
Lj.J. Pavlović ◽  
E.R. Ivanović
Keyword(s):  
Surface Structure ◽  
Apparent Density ◽  
Copper Powder ◽  
Selective Dissolution ◽  
Free Flow ◽  
Electrolytic Copper ◽  
Current Wave ◽  
Electrolytic Copper Powder ◽  
Powder Particles

The surface structure of powder particles, which allows free flow of copper powder, was examined. It has been shown that a sufficiently dense surface structure which permits free flow will be obtained if apparent density is higher than 2.2 – 2.3 g/cm3. Such a surface structure can be obtained by reversing current electrodeposition of powder at considerably lower apparent densities of powder due to selective dissolution of subparticles during anodic time of reversing current wave. The surface structure of copper powder particles is discussed and correlated with the lowest apparent density at which the copper powder can still flow.

scholarly journals The apparent density as a function of the specific surface of copper powder and the shape of the particle size distribution curve

2003 ◽  
Vol 68 (11) ◽  
pp. 903-907 ◽  
Author(s):  
Konstantin Popov ◽  
Predrag Zivkovic ◽  
Snezana Krstic
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Specific Surface ◽  
Size Distribution ◽  
Apparent Density ◽  
Copper Powder ◽  
Distribution Curve ◽  
Particle Size Distribution Curve ◽  
Sulfate Solutions ◽  
Copper Powders

The relation between the specific surface and apparent density of copper powders electrodeposited from acid copper sulfate solutions is established. It is shown that the apparent density is inversely proportional to the specific surface of copper powder. The shape of the particle size distribution curve is also discussed.

scholarly journals The effect of the particle shape and structure on the flowability of electrolytic copper powder. III. Amodel of the surface of a representative particle of flowing copper powder electrodeposited by re

2004 ◽  
Vol 69 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Konstantin Popov ◽  
Snezana Krstic ◽  
Milutin Obradovic ◽  
Miomir Pavlovic ◽  
Ljubica Pavlovic ◽  
...  
Keyword(s):  
Apparent Density ◽  
Copper Powder ◽  
Particle Shape ◽  
Electrolytic Copper ◽  
Electrolytic Copper Powder ◽  
Powder Particles

The structure of the surface of copper powder particles is discussed and correlated with the lowest apparent density at which copper powder can still flow. It is shown that such structures can be easily obtained in the electrodeposition of powders in reversing current regimes.

scholarly journals The representative particle of copper powder and branch of copper dendrites

2002 ◽  
Vol 67 (12) ◽  
pp. 861-866 ◽  
Author(s):  
Konstantin Popov ◽  
Nebojsa Nikolic ◽  
Zlatko Rakocevic
Keyword(s):  
Specific Surface ◽  
Apparent Density ◽  
Powder Particle ◽  
Copper Powder ◽  
Copper Powders ◽  
Electrochemically Deposited ◽  
Size And Morphology

Electrochemically deposited copper powders, which are formed of particles of different size and morphology, are characterized by some properties like specific surface and apparent density. Aprocedure of the determination of a representative powder particle, exhibiting the same values of specific surface and apparent density as the powder is proposed. The proposed procedure also permints an explanation of the branching of copper dendrites.

Rock density from borehole gravity surveys

Geophysics ◽  
1983 ◽  
Vol 48 (3) ◽  
pp. 341-356 ◽  
Author(s):  
T. R. LaFehr
Keyword(s):  
Bulk Density ◽  
Apparent Density ◽  
Density Change ◽  
Large Radius ◽  
Rock Density ◽  
Density Anomaly ◽  
Poisson Jump ◽  
The Difference ◽  
Well Data ◽  
Station Location

The borehole gravity meter (BHGM) is recognized as an important logging tool for obtaining formation bulk density. In general, however, the difference between two gravity observations vertically separated in a well leads to an apparent and not the actual bulk density. BHGM‐derived apparent densities are equal to the formation bulk densities when the instrument passes through beds which are horizontal, infinitely extended laterally, uniformly thick, and constant in density. For many applications, departures from these assumed conditions are so slight that their effects can be ignored, and the BHGM essentially yields bulk density with a large radius of investigation. In the presence of anomalous masses, significant distortion in formation bulk density is possible. The apparent density anomaly produced in the well by an elongated, offset density contrast is proportional to the angle subtended by the density‐change interface. For a density‐change boundary having circular symmetry with respect to the well, the apparent density anomaly at the center of the bed is proportional to the sine of the subtended angle. Because the distortion in bulk density is the same above a horizontal boundary as it is just below (in the limit, at the boundary, for a normally incident well), an abrupt change in apparent density is equal to the real density change at the boundary. This change in density, termed “the Poisson jump,” is independent of geometry; our ability to measure it, however, is a function of station location with respect to the geologic bodies. Two methods are suggested for obtaining bulk densities from BHGM apparent densities: (1) by obtaining two stations just outside as well as just within the zone of interest, the Poisson jump can be approximated and added to an independent density source (e.g., the gamma‐gamma log), and (2) the apparent density anomaly within the formation of interest can be derived by modeling (perhaps based on seismic or well data) and added to the BHGM‐determined densities. Thinner beds can be studied with the BHGM than generally believed, even with much greater station spacing.

scholarly journals Physical modeling of representative particles of electrodeposited copper powders

2006 ◽  
Vol 71 (4) ◽  
pp. 397-400 ◽  
Author(s):  
Konstantin Popov ◽  
Nebojsa Nikolic ◽  
Snezana Krstic ◽  
Miomir Pavlovic
Keyword(s):  
Cross Sections ◽  
Copper Powder ◽  
Physical Modeling ◽  
Copper Powders

A method for the estimation of the size of the representative particle of a copper powder is given. Cross sections of representative particles of flowing and non-flowing powders estimated by this procedure are also presented.

Expansion Behavior of Iron-Copper Compact from (FeCu) Pre-Alloyed Powder

2007 ◽  
Vol 534-536 ◽  
pp. 517-520
Author(s):  
Youn Che Kim ◽  
Myung Jin Suk
Keyword(s):  
Copper Powder ◽  
Copper Content ◽  
Liquid Copper ◽  
Alloyed Powder ◽  
Maximum Expansion ◽  
Iron Copper ◽  
Expansion Behavior ◽  
Expansion Mechanism ◽  
Copper Powders ◽  
Powder Content

Dilatometric curves of iron-copper compact made from elemental or pre-alloyed powder were compared in order to study its expansion mechanism. The compacts from a mixture of elemental iron and copper powders showed the maximum expansion at the copper powder content of 7.44mass% and at the sintering temperatures above the copper melting-point. In the case of the compacts from a mixture of iron pre-alloyed powder of (Fe- 3.44mass%Cu) and copper powder, the maximum expansion which is lower than the former case was obtained at the additive copper powder content of 4.00mass%. But the compact from a mixture of iron pre-alloyed powder of (Fe-7.18mass%Cu) and copper powder showed only shrinkages at any additive copper powder content. The penetration of liquid copper into the interstices between solid grains was observed in all sintered compacts. The iron-copper compacts containing the same content of copper powder showed a very different expansion behavior depending on the amount of copper content in the starting iron raw powder.

Synthetic reactions by complex catalysts. XII. Copper-catalyzed reaction of isocyanide with alcohol

1969 ◽  
Vol 47 (7) ◽  
pp. 1217-1222 ◽  
Author(s):  
Takeo Saegusa ◽  
Yoshihiko Ito ◽  
Shiro Kobayashi ◽  
Kiwami Hirota ◽  
Nobuyuki Takeda
Keyword(s):  
Allyl Alcohol ◽  
Ternary Complex ◽  
Catalyst Activity ◽  
Metallic Copper ◽  
Copper Oxides ◽  
Metal Compounds ◽  
Alkyl Isocyanide ◽  
Unsaturated Alcohols ◽  
Synthetic Reactions ◽  
The Difference

The reaction of alkyl isocyanide with alcohol to produce alkyl formimidate requires catalysis by metal compounds. The catalysts are classified into two groups. The first group includes metallic copper, and the oxides of copper (Cu (I) and Cu (II)), silver, and mercury, which induce the isocyanide reactions of various alcohols including saturated and unsaturated alcohols and amino-alcohol. The second group catalysts are the chlorides of copper (Cu (I)), silver, zinc, and cadmium, which cause the reactions of isocyanide only with special alcohols having strong coordinating tendencies toward the catalyst, as being exemplified by allyl alcohol and β-N,N-dimethylaminoethanol. Among these catalysts, metallic copper and copper oxides are the most effective and give the products almost quantitatively. The difference in catalyst activity between the two groups of catalysts has been explained by assuming a ternary complex consisting of the catalyst, isocyanide, and alcohol as the site of reaction.

Liquid supercoolings and droplet cooling rates of remelted argon-atomized Fe–30Ni powder particles

1988 ◽  
Vol 3 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Matthew R. Libera ◽  
Pedro P. Bolsaitis ◽  
R. Erik Spjut ◽  
John B. VanderSande
Keyword(s):  
Standard Deviation ◽  
Cooling Rate ◽  
Metal Droplet ◽  
Liquid Droplets ◽  
Interfacial Velocity ◽  
Gas Atmosphere ◽  
History Of ◽  
Powder Particles ◽  
The Difference ◽  
Individual Particles

Individual particles of argon-atomized Fe-30Ni powder are electrodynamically levitated and remelted by a CO2 laser pulse. The thermal history of each droplet during remelting and solidification is monitored by single-color radiation pyrometry at each of three wavelengths (850, 750, and 550 nm). Experiments are done in an atmosphere of either air or nitrogen. The average supercooling of six experiments performed in nitrogen is 298 K with a standard deviation of 14 K. This value is of the same order as several others reported in the literature using bulk levitation and emulsification techniques. The average supercooling of seven experiments performed in air is 163 K with a standard deviation of 20 K. The difference suggests that oxides are forming in the air-remelting experiments and catalyzing nucleation at relatively low supercoolings. The average cooling rate of the liquid droplets prior to solidification in nitrogen is 1.5 × 105 K/s. This measured cooling rate is somewhat higher than that predicted by Newtonian heat flow modeling, and the difference is attributed to radiative losses not considered in the Newtonian model. The measured cooling rate is used to estimate the total heat transfer coefficient characterizing cooling of a small metal droplet in a quiescent gas atmosphere. A lower bound of 1.5 × 106 K/s on the droplet heating rate during recalescence and a minimum average liquid/solid interfacial velocity during recalescence of 0.1 m/s are estimated.

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