Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Search
Advanced search
OR
Browse
Search
Volume 21, Issue 12
Displaying 1-14 of 14 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • [title in Japanese]
    Hitoshi EMI
    1984 Volume 21 Issue 12 Pages 746
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.746
    JOURNAL FREE ACCESS
    Download PDF (1662K)
  • Preparation of ultrafine ceramics powders by hydrogen, nitrogen and oxygen plasmas
    Masahiro UDA, Satoru OHNO, Hideo OKUYAMA
    1984 Volume 21 Issue 12 Pages 747-752
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.747
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Ultrafine powders (below 0.1μm) of nitrides (TiN, ZrN) oxides (MgO, Al2O3, WO3, Nb2O5, MoO3) and carbides (WC, SiC, TiC) were directely obtained from massive molten metals or ceramics by using an arc melting technique in an atmosphere of nitrogen or hydrogen or oxygen at 0.1MPa pressure.
    The apparatus for producing ultrafine ceramics powders is basically an arc melting apparatus, which consists of an arc melting chamber with six electrodes, ultrafine powder collecting part (filter paper collection type), gas supply and circulation system, and power source of electric welding.
    The sizes, figures and chemical composition and crystal structures obtained were determined by electron microscorpe, X-ray diffraction and chemical analysis.
    It is estimated that ultrafine ceramics powders were formed by mutual reactions between plasma gas (hydrogen, nitrogen and oxygen atom) and evaporated materials where a kind of enhanced evaporation to be caused by evolution phenomenon of super-saturated gas from molten massive material takes place.
    View full abstract
    Download PDF (5165K)
  • Measurement and Classification of Submicron Particles by Differential Mobility Analyzer and Screen-type Diffusion Battery
    Chikao KANAOKA, Yoshio OTANI, Hitoshi EMI
    1984 Volume 21 Issue 12 Pages 753-758
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.753
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Performances of a Differential Mobility Analyzer (DMA) and a Screen-type Diffusion Battery (SDB) for the measurement of submicron particles are studied, and the applicability of these instruments for the generation of submicron test aerosols is investigated since both instruments measure particle size after classifying particles according to electric mobility and Brownian diffusivity, respectively.
    As a sizer, both DMA and SDB have sufficient performances for submicron particle giving the same measurement result of particle size. As a generator, (1) DMA classifies aerosol into monodisperse particles (geometric standard deviation σg<1.1) with low concentration. It is, hence, preferable for the generation of very monodisperse aerosol unless high concentration is required. (2) SDB is not preferable for the generation of monodisperse aerosols by itself since the classification characteristic is poor in large particle size region. Thus, SDB is combined with an inertial classifier (parallel fiber screens), and it makes it possible to generate high concentration aerosol with fairly high monodispersity (σg≈1.5). Therefore, the combination of SDB and parallel fiber screens is recommended for the generation of a fairly monodisperse aerosol if high concentration is required.
    View full abstract
    Download PDF (609K)
  • Generation of Metal Ultra-Fine-Particles via Gas-Phase Chemical Reaction
    Akinori YOSHIZAWA, Ken-ichi OTSUKA
    1984 Volume 21 Issue 12 Pages 759-767
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.759
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Ultra fine particle/powder (UFP) of metal is generated by hydrogen reduction of MCl2 (M=Ni, Co, Fe) vapor. The effect of reaction temperature, hydrogen flow rate, residence time and total flow rate are discussed and it is concluded that the partial pressure of MCl2 (g), PMCl2, has the greatest influence on the average particle size. Smaller PMCl2 gives smaller median diameter.
    The particle size distributions are almost log-normal and their geometric standard deviations distribute between 1.36 and 1.60 independently on the median diameters.
    A simple model without any adjustable parameters is proposed based on the following assumputions;
    1. the reaction is instantaneous irreversible one and the initial reaction product is metal atom or cluster (called monomer),
    2. because of very high supersaturation, monomers can start coagulation/coalescence among themselves.
    The numerical computation was done and compared with the experimental result. It is concluded though this model is very simple it explains the experiments facts fairly well.
    View full abstract
    Download PDF (1959K)
  • A New Apparatus for Particle Size Measurement by the Method of Centrifugal Sedimentation
    Masatumi ARAKAWA, Gen SHIMOMURA, Akira IMAMURA, Naohiko YAZAWA, Noriyo ...
    1984 Volume 21 Issue 12 Pages 768-773
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.768
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    For the purpose of measuring particle size distributions, we have developed a new apparatus consisting of an imbalance measuring unit with a rotor and a personal computer.
    The imbalance of the rotor caused by the centrifugal sedimentation of the particles in the cell installed in it was detected with the mechanism of the balancing machine and gave the particle size distribution with the aid of the computer.
    Some test measurements were carried out with this apparatus under the following condition. The rotation of the rotor was increased linearly before a set time Tc, After Tc it was set at a constant revolution during the operation.
    This was done in order to shorten the settling time of the particles and to extend the measuring size range.
    The result obtained with the changing rotation gave similar distributions to those with a constant rotation using the same method previously reported by the authors.
    Finally, a comparison with other measurements showed that the results were in good agreement with the sedimentation balance and were finer than the electric resistance and the photo extinction method.
    View full abstract
    Download PDF (570K)
  • Reformation of fine powdery materials through mechanochmiecal effects
    II. Change in the sintering behavior due to mechanical activation
    Tetsushi IWAMOTO, Mamoru SENNA
    1984 Volume 21 Issue 12 Pages 774-777
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.774
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Fine grained, well-dispersed pure α-Al2O3 was ground in a centrifugal ballmill, compressed under 18 and 100MPa, and fired in air at 1050-1550°C. For dense compacts, the sinterability of the activated material was higher up to the relative density, ρF, 85%. However, ρF was much lower for the ground material, when the compact was made at a lower pressure, presumably because of the inhomogeneity of the compact including hard aggregates. SEM observation revealed that the appreciable neck-and grain growth took place at temperatures as low as 1100°C for the activated material due to the enhanced surface diffusion.
    View full abstract
    Download PDF (1431K)
  • A New Production System of Ultrafine Metal Particles by Hydrogen Plasma in an Arc
    Kenji FUJII, Masahiro INOKI, Tohei YOKOYAMA
    1984 Volume 21 Issue 12 Pages 778-782
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.778
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A production system of ultrafine metal particles has been designed and manufactured to examine its industrialization. In this system, metal powders are produced by arc melting in hydrogen and inert gases. The particle generator, a kind of arc furnace, was newly improved so as to produce fine particles and to feed a raw metal rod.
    The generation rate of ultrafine metal particles became higher with the increasing partial pressure of hydrogen in atmosphere. The generation rate of iron particles was about 30g/h in 50% hydrogen atmosphere (5kW). The diameters of Fe, Cu and Al particles were found to be from 10 to 100nm by the use of a transmission electron microscope.
    View full abstract
    Download PDF (2024K)
  • [title in Japanese]
    Hirotsune YASUMI, Nagayoshi MYO, Sizuka SAKASHITA, Shimesu MOTOYAMA
    1984 Volume 21 Issue 12 Pages 783-786
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.783
    JOURNAL FREE ACCESS
    Download PDF (1809K)
  • Development of Ultrafine Spherical Polymethyl-metacrylate Powder and Its Application
    Susumu KAWASE
    1984 Volume 21 Issue 12 Pages 787-790
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.787
    JOURNAL FREE ACCESS
    Download PDF (1601K)
  • Interactions of Rod-like β-FeOOH with Spherical Latex Particles
    Yoshio KITAZAWA, EGON MATIJEVIC
    1984 Volume 21 Issue 12 Pages 791-796
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.791
    JOURNAL FREE ACCESS
    Download PDF (583K)
  • [title in Japanese]
    Saburo YASHIMA
    1984 Volume 21 Issue 12 Pages 797-800
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.797
    JOURNAL FREE ACCESS
    Download PDF (474K)
  • [title in Japanese]
    1984 Volume 21 Issue 12 Pages 801-803
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.801
    JOURNAL FREE ACCESS
    Download PDF (329K)
  • [title in Japanese]
    1984 Volume 21 Issue 12 Pages 804-806
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.804
    JOURNAL FREE ACCESS
    Download PDF (348K)
  • [title in Japanese]
    1984 Volume 21 Issue 12 Pages 807-819
    Published: December 10, 1984
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.21.807
    JOURNAL FREE ACCESS
    Download PDF (3700K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top