粉体および粉末冶金
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
28 巻, 2 号
選択された号の論文の6件中1~6を表示しています
  • 黒木 英憲
    1981 年 28 巻 2 号 p. 47-54
    発行日: 1981/02/25
    公開日: 2009/05/22
    ジャーナル フリー
  • 大槻 悦夫, 増田 良道
    1981 年 28 巻 2 号 p. 55-60
    発行日: 1981/02/25
    公開日: 2009/05/22
    ジャーナル フリー
    For the sintered WC-Co alloys of different microstructure, domain size and root mean squared strain of the WC phase and residual stress in the WC and Co phases were measured on the ground and annealed surfaces by means of X-ray diffraction method. With varying of the microstructure the root mean squared strain and the domain size in the ground surface changed in a given range. The root mean squared strain decreased linearly with an increase of annealing temperature and settled down to about 1.4×10-3 at a given rate, independent of the microstructure. The recrystallization temperature of WC phase in the alloys lowered with an increase of the Co-content between 800 and 1000°C, while the hot-pressed WC recrystalized at 1200°C. The maximum residual stress of about 2.5 GPa in the WC phase in ground surface, was found in a fine grained WC-6wt%Co alloy. The residual stress was almost released by removing Co from the surface layer or by annealing at 800°C, which was considerably lower than the annealing temperature of (1000-1200°C) for stress-relief in the hot-pressed WC.
  • 鈴木 寿, 林 宏爾, 高嶋 好夫, 中山 文夫
    1981 年 28 巻 2 号 p. 61-66
    発行日: 1981/02/25
    公開日: 2009/05/22
    ジャーナル フリー
    Mechanical properties such as transverse-rupture strength and plastic deformation of WC-Ni and WC-fl-Ni alloys with or without additional carbides were studied mainly at 873-1273K in comparison with Co-bonded WC base alloys.
    It was found that Ni-bonded alloys showed generally a lower strength and larger plastic deformation than those of Co-bonded alloys, but this tendency became smaller in f contained alloys with increasing test temperature and decreasing carbon content. It was also found that the addition of Cr3C2 was most effective for improving the mechanical properties of Ni-bonded WC base alloys.
  • 鈴木 寿, 林 宏爾, 久保 裕, 〓 裕康
    1981 年 28 巻 2 号 p. 67-69
    発行日: 1981/02/25
    公開日: 2009/05/22
    ジャーナル フリー
    The high temperature bend-deformation characteristics of TiC-Mo2C-(TiN)-Ni cermets were studied at 873-1273K in relation to the carbon content. It was found that the plastic deformation of the cermets began to take place at about 873K, and it was suppressed with higher carbon content in the temperature range up to about 1073K; but at the higher temperature the effect of carbon content was reversed. The TiN contained cermet showed a smaller plastic deformation than the conventional cermets independently of test temperatures and carbon contents. The effect of carbon content in the cermets was attributed to the variation in the carbide grain size which is a function of carbon contents.
  • 金丸 文一, 小田 喜一, 吉尾 哲夫, 島田 昌彦, 高橋 克明
    1981 年 28 巻 2 号 p. 70-76
    発行日: 1981/02/25
    公開日: 2009/12/04
    ジャーナル フリー
    Crystallization of a SrO-B2O3-SiO2-Fe2O3 glass was investigated to elucidate the precipitation process of SrFe12O19 from the glass matrix.
    The results obtained are as follows; an unidentified crystal phase, X-phase, precipitates by heating the glass in the temperature range from Tg (546°C) to 750°C. The X-ray diffraction lines of the X-phase are well indexed with assuming a cubic unit cell with α=7.584Å. In the temperature range from 650°C to 750°C, 4SrO⋅B2O3⋅SiO2 precipitates in the vicinity of the glass surface and gradually grows toward the inside of the glass.
    SrFe12O19 co-precipitates with 4SrO⋅B2O3⋅SiO2 in the temperature range from 750°C to 850°C. 4SrO⋅B2O3⋅SiO2 has crystallized rapidly in the whole region of the glass and no X-phase is observed in that temperature range. The amount of SrFe12O19 with heating time changes relatively in the same manner as that of 4SrO⋅B2O3⋅SiO2. Based on these results, hexagonal platelets of SrFe12O19 with a dimension of%cong; 0.3μm are obtained as a precipitate from the glass by the heat-treatment at 800°C for 5 hr.
  • 岩津 修, 渡辺 〓尚
    1981 年 28 巻 2 号 p. 77-79
    発行日: 1981/02/25
    公開日: 2009/05/22
    ジャーナル フリー
    During sintering of porous compacts of iron-lead-copper mixed powders, the liquid lead which generated over the melting point of lead disolves the copper particles and the liquid of lead-copper spreads into inherent fine voids in the compact about 700°C. As the consequence, new coarse pores are formed at the original location of the lead particles and this type of residual pore is called "melt-off pore".
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