Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Volume 36, Issue 8
Displaying 1-8 of 8 articles from this issue
  • Yoshishige ENDO, Masahiko ONO, Junichiro TSUBAKI
    1999 Volume 36 Issue 8 Pages 592-598
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    Flying height of magnetic head in hard disk drives has been markedly reduced in proportion to an increase in recording density, resulting in a large head-disk stiction. One of the techniques for overcoming this problem is to use laser texturing. The laser can create bumps with a typical height of 20-30nm and a diameter of 10μm, although a smaller bump diameter is needed to obtain better tribological performance. We therefore studied a precise bump-diameter control process with ultla-fine particles (UFPs) of SiO2 and a dry etching process. UFPs of 0.3μm diameter were coated on a disk surface by dipping or an ink-jet method, and the surface was etched by oxygen. After removing the UFPs, the formed bumps were measured to have a height of 10-20nm and diameter of 0.21μm. The diameter were about the same as the UFP diameter.
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  • Masaru OTANI, Tomoyuki UCHIYAMA, Kunio SHINOHARA, Toshiharu SHIBATA, K ...
    1999 Volume 36 Issue 8 Pages 599-605
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    The effects of particle size and shape of artificial polycrystal diamond grain were studied. The relationship between particle size and lapping characteristics was explained by a stress-strain relation between the work and lapping grain, and it was confirmed that the lapping rate is proportional to the square of particle size and the surface roughness is proportional to it. Furthermore, it is possible to prepare lapping grain with a high lapping rate and small surface roughness by modification of particle shape. An empirical formula which estiamtes the lapping rate from particle shape was obtained.
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  • Hiroyuki IWATA, Shigehisa ENDOH, Hitoshi OHYA, Shigeki KOYANAKA
    1999 Volume 36 Issue 8 Pages 606-612
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    In order to evaluate the surface roughness of spherical Al2O3 granules, we applied an inclined vibrating plate for the separation of granules according to the frictional properties. The behavior of granules on the inclined vibrating plate was of stochastic characteristics which may be caused by a small number of microscopic protrusions on the surface of the granules due to imperfect preparation.
    The stochastic behavior was especially observed as a feature of less frictional particles. We obtained quite a good correlation between circularity of 2D image of granules and their frictional properties, which suggested a possibility of arranging desired shape. We have proposed an equation for estimating the separation kinetics for particles which display stochastic bahavior with steady transition probabilities.
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  • Kunio KATO
    1999 Volume 36 Issue 8 Pages 613-619
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • Yoshiro FUNAKOSHI
    1999 Volume 36 Issue 8 Pages 620-629
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • Kozo YOKOTA
    1999 Volume 36 Issue 8 Pages 630-632
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • Jun OSHITANI
    1999 Volume 36 Issue 8 Pages 633-635
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • Hiroyuki KOHAMA
    1999 Volume 36 Issue 8 Pages 636-644
    Published: August 10, 1999
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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