巻号一覧
28 巻, 6 号
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高野 幹夫, 武田 保雄1981 年 28 巻 6 号 p. 203-209
発行日: 1981/09/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (444K) -
下飯坂 潤三, 横山 秀吉, 中塚 勝人1981 年 28 巻 6 号 p. 210-213
発行日: 1981/09/25
公開日: 2009/05/22
ジャーナル フリーMagnetite thin films of about 0.3 micron thickness were prepared by following procedure. Magnetic fluid, which was composed of magnetite colloid, oleate as dispersing agent and decane as base solvent was spread on polished alumina plates. After the plates were dried, they were put into silica tube and heated at 500°C in CO-CO2 gases mixture so as to decompose the residual solvent and organic surfactant in spread film, keeping the magnetite phase unchanged. Then the plates were separately sintered in an atmosphere of about 10-5 Torr. at various temperatures, in order to controll the grain size of magnetite in the film.
The saturation induction of 5 KG, remanent induction of about 3 KG and coercive force of 400 Oe were obtained by selecting the sintering temperature between 650 and 750°C. Aluminum solved into magnetite at higher temperature, resulting in the decrease of saturation induction.
According to the observation of microstructure, it seemed that the densification of magnetite him by sintering was not enough, presumably due to the large volume ratio of hydrocarbon (surfactant) to magnetite colloid in spread film.
The magnetite thin film obtained here exhibited the increase of coercive force up to 1200 Oe by oxidizing it in an air.抄録全体を表示PDF形式でダウンロード (1622K) -
宇津木 弘, 遠藤 敦, 鈴木 昇, 花岡 信子, 曽場 隆, 菅野 彰1981 年 28 巻 6 号 p. 214-219
発行日: 1981/09/25
公開日: 2009/05/22
ジャーナル フリーThe surface-treatment of silica gels was performed by the refiux method where the water absorbed in the silica gels was removed previously by boiling them in the long carbon chain hydrocarbon with high boiling point, thereafter an alcohol having a similar boiling point as that of hydrocarbon was added to these suspensions and reacted with silica gels. The effect of surface-treatment by the reflux method on the surface properties, e.g., surface area and pore size distribution was investigated. The followings were confirmed; (1) both the adsorbed amounts of argon at 77K on the silica gels dehydrated in the boiling hydrocarbon and the surface areas showed the decrease in comparison with those of the original silica gel. These trends were appreciable with raising the temperature for dehydration and a 10% decrease was observed in both adsorbed amount on silica gel dehydrated at 250°C and the surface area. (2) both the adsorbed amount on the silica gels treated with alcohol after dehydration and the surface area showed an appreciable decrease according to the degree of surface-treatment and, the length of carbon chain of each surface group. After removing the surface group by the heat treatment, both adsorbed amount and surface area were found to be similar to those of the silica gel dehydrated in the boiling hydrocarbon, but showed still low value in comparison with those of original silica gel. From these results, it would be concluded that the dehydration of silica gels resulted in the surface contraction whereas the reaction of alcohol with silica gel did not affect the surface properties of the substrate.抄録全体を表示PDF形式でダウンロード (369K) -
貞廣 孟史1981 年 28 巻 6 号 p. 220-224
発行日: 1981/09/25
公開日: 2009/12/04
ジャーナル フリーEffect of additional carbides on the fracture toughness, and the relationship between the fracture tough-ness and the crack resistance of cemented carbides were investigated.
Results obtained are as follows. (1) The fracture toughness in relation to the hardness of cemented carbides is not changed by addition of TiC and NbC up to 20 to 30 vol%, while it decreases with addition of TaC and large amount of TiC. The fracture toughness of WC-TiC-Co alloys decreases with addition of TaC. (2) The crack resistance of cemented carbides has a correlation to the fracture toughness. And the crack resistance shows a linear relation to the critical strain energy release rate when Vickers hardness of these alloys is above 1200.抄録全体を表示PDF形式でダウンロード (290K) -
河野 通, 西野 良夫1981 年 28 巻 6 号 p. 225-230
発行日: 1981/09/25
公開日: 2009/05/22
ジャーナル フリーBy adding phosphorus to Cu-Sn mixed powders and pressing those at relatively high pressure, the compacts are strengthened at low sintering temperature of about 650°C. Besides, in the case of about 0.8% addition of phosphorus, the compacts swell and their porosity increases.
By utilizing this phenomenon, we produced the bronze type oil impregnated sintered bearings containing a large amount of lead and graphite, which had high strength and high porosity. For example, the bearing added about 12%Pb and 5% C had the radial crushing strength of about 22 kg/mm2 and the oil content of about 21%.
The bearings were driven under the relatively severe running condition (P=20 kg/cm2, N=4, 000 rpm, PV=2, 000 kg/cm2·m/min) for evaluating the bearing performance. And it was found that the bearing which was added proper amounts of lead (about 6%) showed an excellent performance because lead com-pensated the weak formability of solid lubricant film of graphite. However, the bearing which was added excess amounts of lead (about 12%) showed an inferior bearing performance.抄録全体を表示PDF形式でダウンロード (3169K) -
木下 実, 永田 一三, 寺井 良平1981 年 28 巻 6 号 p. 231-236
発行日: 1981/09/25
公開日: 2009/12/04
ジャーナル フリーGlass-copper composite compacts were studied concerning solidification of radioactive wastes. The powder mixtures of the glass, which was a borosilicate glass containing about 27wt% high-level radioactive wastes (simulated) offered by PNC, and electrolyzed, fine copper powder were subjected to pressure sintering.
At first, sintering behavior of the mixtures and thermal properties of the compacts were investigated. The mixtures sintered almost to full densities at the temperatures above the yield point of the glass, when the copper content was not so much. The thermal conductivity of the compact containing 30wt% copper was about 4.5 times higher than that of original glass.
In order to obtain long size composite compacts, a continuous pressure sintering apparatus was built as trial. Using the mixture containing 30wt% copper powder. the compacts of the diameter of 5 cm and of the length exceeding 30 cm were successfully prepared at the sintering conditions of 560°C and 150 kg/cm2.抄録全体を表示PDF形式でダウンロード (3960K)
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