巻号一覧
14 巻, 5 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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C.G. Goetzel, J.B. Rittenhouse1967 年 14 巻 5 号 p. 195-202
発行日: 1967/08/25
公開日: 2009/12/04
ジャーナル フリー粉末冶金の製品は,一般の航空方面への応用とともに,宇宙衛星の部品として利用されるようになった.宇宙衛星の関係部品は,高度に特殊化された目的を満足させるたあに,広範な発展計画を必要とするものである.この報告では,宇宙衛星に対するいくつかの粉末冶金の応用の紹介と,実際に軌道にのった宇宙衛星に使用された粉末冶金部品および材料の二,三の例について論ずる,粉末冶金製品の例として,93日間の飛行に成功したExplorer皿、のテープレコーダー中の焼結ブAンズベアリングがあり,また航空用衛星(その中には7カ月も活動したものもある)内の,自転抑制装置に用いられた焼結マグネットなどがある.化学的浸食熱応九融点近くの表面温度などに対する抵抗が要求されるようないわゆる高温熱流に対しては,Agを溶浸させたWが用いられる.これは粉末冶金法によってのみ作られるものである.この物質を十分に管理された製造工程のもとで製作するために,複合材料に最適の実用性質を発揮させるような広範な計画が開始された.粉末冶金法で製造されたBeの利点については,特に目下計画中,あるいは設計中の人間宇宙ステーションの表面材料として,および流星群の遮蔽防御などへの応用に対して検討されている.抄録全体を表示PDF形式でダウンロード (639K) -
銅系について石田 制一, 谷内 剛1967 年 14 巻 5 号 p. 203-212
発行日: 1967/08/25
公開日: 2009/05/22
ジャーナル フリーA new sintered copper-base brake lining for disc brake of railroad cars, torque converters and transportation machines has been developed.
The lining material contains copper, tin and lead as metallic component, and graphite and silica or alumina as non-metallic one. Copper and tin form a wear resistant matrix as "Sintered bronze". Various characteristics could be obtained by incorporating the solid lubricant (graphite and lead) and wear resistant element (silica and alumina).
Coefficient of friction and wear rate of the lining materials are given in dry and wet conditions.抄録全体を表示PDF形式でダウンロード (2809K) -
合金元素を低減した焼結鋼について木下 禾大, 徳永 洋一, 谷口 勲1967 年 14 巻 5 号 p. 213-220
発行日: 1967/08/25
公開日: 2010/07/12
ジャーナル フリーThe sintering and age-hardening-characteristics of 18 Ni-7Co-5Mo sintered steel were reported before. In the present paper, a composition of 78Fe-12Ni-5Co-5Mo was chosen for examining the structural and mechanical properties of the sintered steel which was reduced effectively in the amount of alloying elements. Specimens were prepared by mixing reduced iron powder with powders of alloying element, compacted mainly at 6t/cm2 and sintered in hydrogen for lhr at 1300°C. Subsequently, the sintered compacts were aged for 5hrs at 500°C. The results are summarized as follows ;
1) The variations of concentration of alloying elements in the sintered steel were determined by electron-probe' microanalyses. The concentrations were 8-12% for nickel, 4-6% for cabalt and for molybdenum. From these results, therefore, the structural characteristics of the sintered compact may be estimated as follows ; Ms-temperature ; 465-260°C, age-hardenability ; 3-14 HRc and tensile strength after aging; 80-150kg/mm2.
2) The mechanical properties of sintered steel are mostly determined by chemical composition and also by relative porosity. An empirical relationship is established between the porosity and yield strength of sintered steel, given by; Y. Ss/Y. Sm=1-1.58ε2/3, Where, Y. Ss and Y. Sm are the yield strengths of the sintered and forged steel respectively, and & is relative porosity. This relationship shows good agreement among the results obtained with 12Ni-5Co-5Mo and 18Ni-7Co-5Mo steels. The transverse-rupture strength, however, is markedly affected by the stress concentration generated by pores. Consequently, the ratio of the strength of the sintered steel to that of the forged steel is lower than the ratio of tensile property.
3) Addition of copper to sintered steel resulted in higher tensile strength, but in lower transverse-rupture strength, which might be due to the improved age-hardenability in the martensitic matrix. Attempts to obtain compacts with higher density by adding phosphor and boron has been unsuccessful, probably due to the extremely brittle nature of the sintered compacts.抄録全体を表示PDF形式でダウンロード (4466K) -
西本 幸三, 五嶋 康雅, 中西 典彦, 可知 〓次1967 年 14 巻 5 号 p. 221-225
発行日: 1967/08/25
公開日: 2009/12/04
ジャーナル フリーFine particles of high-purity barium titanate from a minimum of 500A upwards were prepared. by the thermal decomposition of barium titanyl oxalates, BaTiO(C2O4) 2⋅4H20, at 600-1100°C. The effective dielectric constant was measured with the particles dispersed in Araldite resin. The following results are of interest: (1) In the case of fine particles of 500-700A, the effective dielectric constant delineates a smooth curve with temperature and the ferroelectric Curie peak moves to low temperature. (2) From X-ray diffraction analysis, the tetragonality decreased with decreasing particle size, thus leading to cubic symmetry.
A brief discussion was given to the correlation between the decrease in tetragonality and the shift of the Curie point.抄録全体を表示PDF形式でダウンロード (1602K) -
西本 幸三, 五嶋 康雅, 中西 典彦, 可知 〓次1967 年 14 巻 5 号 p. 226-230
発行日: 1967/08/25
公開日: 2009/05/22
ジャーナル フリーPressure-squeezing effect on the ferro-paraelectric transition of barium titanate and a ceramic body was studied. The remarkable experimental results are as follows : (1) The pressure-sque-ezed barium titanate had a smaller heat of transition at the Curie temperature and a remarkable low dielectric constant which did not show a steep rise at the Curie temperature, 120°C. (2) The steep rise was not observed even when the pressure-squeezed sample had been annealed at 1200°C for 2 hr. (3) The pressure-squeezed sample showed no P-E hysteresis loop and had tetragonal symmetry characterized by broad peaks in X-ray patterns even above the Curie temperature.
It appears that the notable pressure-squeezing effects, i.e., decrease in grain size and formation of mechanical stresses among the crystal grains and of lattice defects, especially stacking faults, cause the hindrance to the displacement of ions and hence to the ferroelectric arrangement of spontaneous polarization.抄録全体を表示PDF形式でダウンロード (4145K)
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