Journal of the Japan Society of Powder and Powder Metallurgy
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
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Volume 57, Issue 10
October
Displaying 1-12 of 12 articles from this issue
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Paper
Paper
  • Effects of Permeability on DC Biased Properties of Powder Cores and Modeling
    Susumu Handa, Yasuo Oshima, Kouta Akaiwa
    2010 Volume 57 Issue 10 Pages 647-653
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.647
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    DC biased magnetic properties of Fe-3 mass % Si powder cores have been measured and compared with calculated values using a nonmagnetic grain boundary (NMGB) model. Aluminum oxide fine powder was added into magnetic powder in order to change permeability and the amount of the powder was 0, 0.25, 0.4, 0.7, 1.0 mass %. DC initial B-H loops were measured and differential permeability was calculated at each magnetic force H. The values were compared with calculated one using the NMGB model which was taken account of gap width distribution. Best agreement of relative inaccuracy was additive amount 0.4 mass %. In that case relative inaccuracy of the powder core was from -0.4 % to 8.4 % with non gap distribution and from -3.00 to 4.00 % with gap distribution. The most improved case was additive amount 0 %. Relative inaccuracy was from -6.0 % to 22.8 % with non gap distribution and from -4.40 to 9.20 % with gap distribution.
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  • Sintering and Mechanical Properties of Fly-ash/NiCr Compacts Prepared by Spark Plasma Sintering
    Mamoru Daio, Kazuhiro Hasezaki, Mariko Hosogi, Ichiro Yoshioka
    2010 Volume 57 Issue 10 Pages 654-659
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.654
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    Fly-ash/NiCr-alloy functionally graded materials (FGMs) plates were prepared by spark plasma sintering (SPS); the plates were 100 mm in diameter and layer thicknesses of 0.6 mm and 1 mm. The plates consisted of stacked layers; the layers had volume ratio compositions of fly-ash/NiCr = (100/0 (A), 60/40 (B), 40/60 (C), 60/40 (B), 100/0 (A)). Two sorts of FGMs specimens with three layers prepared by machined from the FGMs plates with A/B/C/B/A five layers were investigated using a three-point flexural test. One sort of specimens had the normal stacking structure A/B/C, and the other had the reverse structure C/B/A, for the loading nose. After investigating the strengths of these two stacking structures, the fracture origins were observed at the surface of the extending C layer of the A/B/C structures, and of the A layer surface of the C/B/A structures. The deformation mechanism, average strength, and Weibull modulus were ductile, 12.0 MPa, and 5.5, respectively, for the normal A/B/C structure, and brittle, 46.7 MPa, and 13.1, respectively, for the C/B/A reverse structure. The different strengths of the two structures were explained on the basis of the strength of the extending surface layer, A or C, and the residual stress caused by the difference in thermal expansion coefficients of the stacking layers in the two structures. It was concluded that the fracture strengths of stacked FGMs materials were dominated by the stress field between the constituent layers and by the loading direction.
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  • Synthesis of Ti3SiC2 by Pressureless Sintering of Compacted Powder Blends of Ti, SiC, C and TiC
    Hitoshi Hashimoto, Zheng Ming Sun, Yasuhiro Nakatani, Shinya Aoki
    2010 Volume 57 Issue 10 Pages 660-664
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.660
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    Titanium silicon carbide Ti3SiC2, a member of MAX-phase ternary compound ceramics, is expected as a new resistance heating element substituting for conventional ones including rare metals because of its excellent high-temperature oxidation resistance, metal-like electrical conductivity, good machinability and ubiquitous constituent elements. The authors tried to synthesize a large bulk Ti3SiC2 by pressureless sintering of a compacted powder blend of Ti, SiC and C, while the powder compact collapsed during sintering. Causes of the collapse were investigated and based on the investigation results a solution for the problem was found out. The large bulk Ti3SiC2 was synthesized successfully without collapse by the replacement of a part of Ti and C in the starting powders with TiC.
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Special Issue: High Performance Electronic Components, Materials and its Applications
Summarization
Review
  • Invention of Ferrites and 80 Years of Their Growth
    Akira Okamoto
    2010 Volume 57 Issue 10 Pages 667-671
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.667
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    Dr. Takeshi Takei, the professor at Tokyo Institute of Technology, discovered that oxides containing zinc and iron have distinguished magnetic properties. In 1930, Prof. Kato and Prof. Takei applied a patent for their discovery, which was granted in 1932 in Japan.
    Tokyo Denki Kagaku Kogyo (now TDK Corporation) was founded in 1935 to commercialize this newly invented ferrite cores as a venture company originated from the university patent of ferrite
    TDK started mass production of ferrite cores in 1937. Most of the shipped products were used in the local oscillators, mixers, and intermediate frequency transformers of military radios. These are the world first usage of ferrite to radio communication equipments. Ferrite largely contributed to reduce volume and weight of radio receiver compared with air coil.
    Until the end of the World War II, TDK was the only company in the world who could supply ferrite cores. TDK shipped a cumulative total of nearly 5 million pieces of ferrite cores by 1945.
    Many people have believed that Philips invented ferrites and they applied them to radio. But their first patent was applied in 1941 in Netherlands after they examined ferrite samples from TDK. This paper also explains about the patent dispute between Philips and TDK after the World War II which caused such misunderstanding.
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Paper
  • Fabrication of Mg Ferrite/permalloy Magnetic Nano-composites
    Motoki Obata, Masaki Kato, Ken Hirota
    2010 Volume 57 Issue 10 Pages 672-677
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.672
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    Dense {Mg(Fe1-xMnx)2O4/53Fe-47Ni permalloy (0≤x≤0.4)} magnetic nano-composites consisting of spinel and alloy phases have been fabricated from N2-atomized metal particles and fine-powder mixtures of MgO/α-Fe2O3/MnO using a combination of pulsed electric current pressure sintering (PECPS) and hot isostatic pressing (HIP). Fe-Ni permalloy particles were coated with the mixed metal oxide powders homogeneously by passing these mixtures through a narrow gap (1 mm) under high shear compression in Ar. Mixed powder compacts of permalloy with the fine metal oxides were densified into the green bodies having relative densities of 83-85 % under isostatic high pressure of 1 GPa at room temperature. Then green powder compacts were pre-sintered at 823 K for 3 min under a uniaxial pressure of 100 MPa in Ar using a PECPS. The pre-sintered bodies composed of spinel ferrite and permalloy revealed the relative densities of 94-96 %; the mixed metal oxides changed into magnesium spinel ferrites Mg(Fe1-xMnx)2O4 during a short heating time. Then hot isostatic pressing (HIP: (1123 K/6 h/200 MPa-Ar)) was adopted to sinter the pre-sintered bodies into a near full density without an encapsulation, however, a sintering atmosphere control was performed using a ferrite muffle in order to maintain the both phase. Sintered nano-composites with the relative density more than 99.5 % have a saturation magnetization density ≥1 T and moderate permeability values of 30-35 at 10 MHz, which values have been expected from a material design.
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Memorial Lecture of JSPM Award
  • Development of a New Multi Layer Substrate (PALAP) Using Ag-Sn Liquid Phase Sintering Process
    Koji Kondo, Yoshitaro Yazaki, Yoshihiko Shiraishi
    2010 Volume 57 Issue 10 Pages 678-682
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.678
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    In order to construct the multi layers IVH (Interstitial Via Hole) structure with only one time hot pressing; we have developed the new diffusion bonding technology. The liquid phase sintering of Ag-Sn mixed powders (Ag/Sn:65/35 mass%) is utilized for bonding between Copper layers.
    In this paper, the pore formation at Ag and Ag-Sn sintering process was investigated, and the effect of Sn liquid phase on pore formation was discussed. However Ag formed Ag3Sn with the solid diffusion reaction up to 453 K, excess Sn particles exist surrounded with Ag3Sn. While Sn particles are fusible above 494 K, the shell of Ag3Sn is infusible. Pore forms with Sn particles effusion
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Review
  • IP Strategy for Electrical Materials and Components
    Yoichi Oshima
    2010 Volume 57 Issue 10 Pages 683-688
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2497/jjspm.57.683
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    The number of patent for fine particle, one of the hottest topics of electrical materials and components, indicates the steady increase. Although Japanese patent still remains the same number as last decade in this field, Chinese patent has been increased rapidly in recent years.
    IP strategy for electrical materials and components fields is facing the new stages. Advanced IP strategy is tend to cooperative rather than competitive, because recent green related technologies, including new electrical materials and components, put emphasize on sustainable system which require the maximization of the benefit for all participant.
    This article proposed the new IP usage, IP based consortium, which can avoid the patent infringement case among the consortium members. In addition, IP based consortium can be functioned as the neutral and fairness organization to pool members fee and to distribute dividend to the contributors.
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JSPM Announcements
Errata (Vol.57, No.8)
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