粉体および粉末冶金
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
59 巻, 7 号
July
選択された号の論文の11件中1~11を表示しています
研究
研究
  • 水野 勉, 安里 優一, 北村 善紀, 後藤 聖, 渡辺 隆志, 竹増 光家, 新仏 利仲, 天野 秀一, 吉川 紘, 須田 敦
    2012 年 59 巻 7 号 p. 385-390
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Surface rolled sintered gears are expected to be used in automotives. For commercialization of them, a reliable and efficient in-line inspection after rolling is inevitable. The authors have been proposing an eddy current inspection for PM components as a non-destructive, efficient method to be installed in-line. The eddy current depends on the resistivity and the relative permeability of the material to be measured. While those of sintered bodies will be changed by surface rolling as it will accompany with both the densification and the residual stress. In order to use the eddy current method as the inspection of the surface rolled sintered gear, distributions of the resistivity, the relative permeability along with the porosity of the Fe-1.5 Cr-0.2 Mo-0.23 C alloy having 4 different densities, 7.0, 7.25, 7.5 and 7.6, were measured and analyzed.
  • 世利 修美, 西田 拓也, 和田 佳之, 長船 康裕
    2012 年 59 巻 7 号 p. 391-393
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    3Al2O3·2SiO2 (mullite) was obtained by the corrosion reaction of aluminum in ethanol. The aluminum corrosion product and tetraethoxysilane were mixed in the solution. Ammonia water was added into the mixed solution above. When the solution was dried and fired, white powders were obtained. This powder was identified as mullite by X-ray analysis. Distribution analysis and chemical analysis reveal that the average particle size was about 5 μm, and that its impurities were up to 0.1 %.
特集:傾斜機能・生体材料
総報
解説
研究
  • Tatsuya Yonesaki, Akihiko Ito, Takashi Goto
    2012 年 59 巻 7 号 p. 405-409
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Tianium oxynitride (Ti(O, N)) films were prepared on a Ti(C, N)-based cermet substrate by laser chemical vapor deposition using titanium tetraisopropoxide and NH3 as precursors. A mixture of TiO2 and cubic TiO films was obtained at a deposition temperature of 820 K. Single-phase cubic Ti(O, N) films were prepared at 850-1100 K. With increasing deposition temperature from 850 to 1100 K, the lattice parameter of the Ti(O, N) film increased from 0.4194 to 0.4244 nm, as the N to O ratio in the Ti(O, N) film changed from TiO to TiN. Ti(O, N) films consisted of pyramidal grains with a columnar structure. Ti(O, N) films exhibited higher adhesion at higher deposition temperatures and lower total pressures.
  • Jianfeng Zhang, Rong Tu, Takashi Goto
    2012 年 59 巻 7 号 p. 410-271
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Ni-cubic boron nitride (cBN) composites were prepared using Ni and cBN powders by spark plasma sintering at 1073 to 1473 K for 0.6 ks under a pressure of 100 MPa. Densification, microstructure and hardness of the Ni-cBN composites and the phase transformation of cBN to hexagonal BN (hBN) in the Ni-cBN composite were studied. Ni-cBN composites originally containing 10-30 vol% cBN showed the highest relative density of 98 % at 1373 K for 0.6 ks without the phase transformation to hexagonal BN (hBN). The phase transformation of Ni-20 vol% cBN occurred at 1473 K after 0.6 ks and at 1173 K after 1.2 ks. The maximum hardness of 3.5 GPa was obtained in the Ni-cBN composites originally containing 30 vol% cBN sintered at 1373 K for 0.6 ks.
  • Zhao-Xiang Chen, Wen-Xue Wang, Yoshihiro Takao, Terutake Matsubara, Li ...
    2012 年 59 巻 7 号 p. 415-420
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Titanium surface is usually modified using a spark anodizing technique for biomedical application, and the resultant anodic TiO2 layer on the surface plays a crucial role in promoting the favorable biologic response. However, despite the fundamental importance of anodic TiO2 layer, little is known about its long-term stability or changes in vivo. In this study, as a first step to elucidate the surface changes of anodized titanium in vivo, changes in surface characteristics of anodic TiO2 layer arising from water immersion at 37°C were investigated. It was found that after water immersion for 1 week, numerous nanoparticles emerged on the surface of anodized titanium fabricated at a voltage of 200 V, and with the further increase of immersion time, more nanopartiles formed and interconnected with each other, resulting in a nanostructured surface layer. Transmission electron microscopy investigation of anodic TiO2 layer before and after water immersion indicated that water immersion transformed the originally amorphous TiO2 layer into crystalline anatase gradually, and the lap-shear test of oxide layers demonstrated the decreased shear strength with water immersion. In addition, it was found that the increased anodization voltage led to the anodic TiO2 layer with better stability.
  • 荒平 高章, 東藤 貢
    2012 年 59 巻 7 号 p. 421-424
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Recently, in the field of orthopedics, artificial bone substitute has been one of the primary concerns instead of autografts and allografts. The ideal artificial substitutes are biodegradable with adjustable degradation rate that fits in the rate of tissue regeneration and also need enough mechanical properties to support the part of bone defect. In this study, a porous structure of β-TCP was fabricated and collagen coating was introduced to enhance the structural stability and mechanical properties. Compressive mechanical tests were performed to assess the effect of the collagen coating, and the surfaces of the specimens were also observed using FE-SEM to understand the microstructural modification. It was found that the compressive modulus and strength of the porous β-TCP can be effectively improved by collagen coating.
  • 奥平 泰久, 塗 溶, 後藤 孝, 丸森 亮太朗, 依田 正信, 佐々木 啓一
    2012 年 59 巻 7 号 p. 425-429
    発行日: 2012/07/15
    公開日: 2012/11/09
    ジャーナル オープンアクセス
    Metal is currently widely used in dentistry, but it has an aesthetic disadvantage because of its color. In this study, TiO2 films were prepared on titanium used as a dental metal by microwave plasma CVD for use as whiteners.The effects of microwave power (PM) and deposition pressure (Ptot) on the adhesion strength and color of TiO2 coating were investigated. The results suggest that a higher deposition pressure and a stronger microwave power are necessary to conceal the color of titanium and to achieve a white color, while a lower deposition pressure and a weaker microwave power are necessary to obtain good adhesion.
本会記事
feedback
Top