巻号一覧
22 巻, 6 号
選択された号の論文の5件中1～5を表示しています
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軸対称圧縮成形の場合沖本 邦郎, 大矢根 守哉, 島 進1975 年 22 巻 6 号 p. 177-184
発行日: 1975/10/05
公開日: 2009/05/22
ジャーナル フリーVarious practical consolidation processes such as closed die compaction, hydrostatic compaction and dry rubber press are performed, and relations between stresses and densities are investigated. The stresses required in these compacting processes are compared with the yield stress and fracture stress in uniaxial compression test of green compacts.
For a stress state such that σ2=σ3, the following equation is obtained, which gives a relation between stress and density in compacting process:
?? (a=g1(γ), b=g2(γ);both are the function of γ.)
where σ1, σ2, σ3 are the principal stresses and γ the relative density.抄録全体を表示PDF形式でダウンロード (545K) -
沖本 邦郎, 大矢根 守哉, 島 進1975 年 22 巻 6 号 p. 185-191
発行日: 1975/10/05
公開日: 2009/05/22
ジャーナル フリーFracture behaviour of green compacts is investigated under an axi-symmetrical stress condition such that σ2=σ3 in three principal stresses σ1, σ2 and σ3, that is, a uniaxial compression and a compression under hydrostatic pressure.
Relations between σ1 and σ2 at fracture point, and between σ2 and fracture strain ε1f are investigated. The former relation is represented in Rendulic stress plane, where σ2=σ3, by using a parameter γ of relative density. The curves show a fracture condition for green compacts.抄録全体を表示PDF形式でダウンロード (2538K) -
鈴木 寿, 棚瀬 照義, 中山 文夫1975 年 22 巻 6 号 p. 192-197
発行日: 1975/10/05
公開日: 2009/05/22
ジャーナル フリーThis investigation was undertaken to clarify the mechanism of micropore-formation in WC-Co alloys, from the viewpoint that pores would be resulted from coarse Co particles which pre-existed in (WC+Co) mixture. High carbon two-phase WC-Co alloys with about 10 and 20% Co were in vacuum sintered under various conditions, using usually ball-milled mixtures in which some amounts of coarse Co particles were intermixed for a model-experiment, or from which pre-existed coarse Co particles were removed or not.
Results obtained were as follows:1) In case of the low temperature sintering including solid-phase sintering, coarse Co particles in the mixture became Co pools and changed into pores as sintering time increased. In case of the high temperature sintering, those Co pools tended to change rapidly in pores, when the Co content in the alloy was low. 2) Thus, the structural defects such as Co pools and pores were confirmed to be closely related to each other. Pores above mentioned didn't develope in the alloys, for instance, with high Co contents because of the facility of viscous flow of the matrix. 3) The above results in model-experiments were considered to be available also in the usual WC-10% Co alloy. Because, the removal of coarse Co particles which pre-existed in the ball-milled mixture resulted in disappearence of the pores, the dimensions of which corresponded to those of removed Co particles, leading to a sharp increase in the strength of alloys.抄録全体を表示PDF形式でダウンロード (3571K) -
松山 巌, 野呂 孝信, 定村 茂1975 年 22 巻 6 号 p. 198-201
発行日: 1975/10/05
公開日: 2009/12/04
ジャーナル フリーGrain growth of PLZT was investigated as a function of the hot-pressing parameters of temperature, time and pressure. The selected conditions are; temperature range from 1100 to 1250°C, time range from 120 to1440 minutes and pressure range from 0 to 350kg/cm2.
The results indicated that the grain growth depends upon the temperature and time, but does not on the pressure. Grain growth for 8/65/35(La/Zr/Ti) PLZT was expressed as follows; D3=34×10texp(-ΔH/RT), where D is the average grain size in μm unit, t the time in min. T the absolute temperature and ΔH an activation energy. The activation energy of 78 kcal/mol was calculated.抄録全体を表示PDF形式でダウンロード (298K) -
Osamu Yamaguchi, Hichiro Ômaki, Kiyoshi Shimizu1975 年 22 巻 6 号 p. 202-204
発行日: 1975/10/05
公開日: 2009/05/22
ジャーナル フリーAs a raw material for the production of spinel (MgAl2O4) at low temperature, mixed hydroxides were prepared by the simultaneous hydrolysis of magnesium and aluminum alkoxides. These hydroxides were identified as a mixture of 2 Mg(OH)2-Al(OH)3 and boemite gel AlO(OH) and were converted to spinel below 1000°C. The formation mechanism of spinel from these hydroxides was examined by means of X-ray diffraction and thermal analysis. The lattice constant of spinel obtained by heating these hydroxides at 1400°C for 3 hr was 8.088 Å.抄録全体を表示PDF形式でダウンロード (146K)
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