巻号一覧
44 巻, 7 号
選択された号の論文の14件中1～14を表示しています
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下川 勝義, 鈴木 良和, 皆川 秀紀1997 年 44 巻 7 号 p. 641-646
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーTi-Fe alloy is one of the most useful materials for hydrogen storage alloy. In order to improve the absorption-desorption for hydrogen, however, it requires homogeneous structure and microscopically large surface. The effect of microgravity which suppresses the convection of constituents in molten alloy, against nucleation and crystal growth in solution has attracted attention. A preliminary investigation for synthesis of homogeneous Ti-Fe alloy has been examined. Furthermore, fundamental research concerning in the properties of hydrogen storing alloy and crystal structure has been performed. On the relation between hydrogen pressure and concentration of stored hydrogen shown in P-C-T (hydrogen pressure-concentration of stored hydrogen-temperature) curve, large hysteresis and rapid absorption-desorption was observed on the Ti-Fe sample produced at 1050°C under normal gravity. But Ti-Fe alloy produced at 1280°C under microgravity, hydrogen charge or discharge pressure decreased and the gradient of the curve become plateau at 0.5-1.0 hydrogen concentration. In case of the sample produced under normal gravity, heterogeneous composition and dense structure was observed, while homogeneous composition and porous structure was obtained easily in the sample produced under microgravity. Furthermore, powdering phenomenon after cycle of absorption-desorption of hydrogen was not occurred around porous structure produced under both normal gravity and microgravity conditions.抄録全体を表示PDF形式でダウンロード (3887K) -
落合 鍾一, 武田 均, 小嶋 芳郎, 菊原 俊司1997 年 44 巻 7 号 p. 647-652
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーTiAl-TiB2 composites with 0, 10, 15 and 20vol%TiB2 were produced by MA-HIP method using pure Ti, Al and TiB2 powders. Microstructures and mechanical properties of the composites at elevated temperatures were investigated as well as MA process. Obtained results are as follows. The partial amorphization was found during MA process even in powders containing TiB2 particles. Microstructures of HIPed compacts tend to become finer with increase of volume percent of TiB2. Compacts with the addition of TiB2 particles were consisting of TiAl, Ti3Al and TiB2 phases. herefore, it was confirmed that there was little reaction between TiAl and TiB2 particles during sintering. The flow stress was increased with increase of TiB2 volume percent, although the increment of flow stress by the effect of dispersing of TiB2 decreased as the temperature rose. The strain rate sensitivity exponents (m values) were found to be larger than 0.3 at 1373K for any specimen.抄録全体を表示PDF形式でダウンロード (3101K) -
陳 立東, 後藤 孝, 〓 溶, 平井 敏雄1997 年 44 巻 7 号 p. 653-657
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーOxidation behavior of lead telluride (PbTe) and glass-coated PbTe was studied at oxygen partial pressures of 10Pa to 0.1MPa in the temperature range between 700 to 900K. Mass loss was observed at moderately low oxygen partial pressures and at high temperatures, while mass gain was observed at high oxygen partial pressures and at low temperatures. For the samples which showed mass loss, Pb3TeO5 or Pb5TeO7 formed on the PbTe surface. The formation of PbTeO3 layer or Pb2TeO4/PbTeO3 multi-layer caused the mass gain. Oxidation resistance of PbTe was improved by the glass-coating. No mass change was observed up to 20ks.抄録全体を表示PDF形式でダウンロード (1746K) -
南 清隆, 貞野 計, 荒川 剛1997 年 44 巻 7 号 p. 658-660
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーCrystalline powders of Re and Si in the composition ratio varing from Re:Si=1:4 to 2:1 were mechanically alloyed by a laboratory ball mill in an inert atmosphere. In the course of the mechanical alloying reaction, the halo patterns which are characterized as the amorhous alloy powders was not obtained, but the formation of rhenium silicides(ReSi2 and Re5Si3) have been recognized, judging from the measurement of XRD. Moreover, from the electrical conductivity measurement of the rhenium silicide pellets, it was found that the semiconductive phenomena were clearly exhibited in the range from room temperature to about 473K and the activation energies were 1.23eV for Re5Si3 and 0.27 eV for ReSi2, respectively.抄録全体を表示PDF形式でダウンロード (156K) -
杉本 光男1997 年 44 巻 7 号 p. 662
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (85K) -
柿崎 浩一, 平塚 信之1997 年 44 巻 7 号 p. 663-667
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーAcicular barium ferrite fine particles doped with Co2+ ions and Ti4+ ions were prepared by a conventional sintering method. We investigated fine structure of the acicular BaCoxTixFe12-2xO19 (X=0 and 0.7) particles using x-ray diffractometer (XRD) and high resolution transmission electron microscope (HR-TEM). From x-ray diffraction patterns of them, the acicular BaCoxTixFe12-2xO19 particles had a hexagonal structure of the magnetoplumbite type. These acicular BaCoxTixFe12-2xO19 particles had the long axis of about 1.0μm, the short axis of 0.09μm and the aspect ratio of about 11. It was observed by dark field images of TEM that one acicular BaCoxTixFe12-2xO19 particle consisted of some crystallites and the c-axis of them were lying perpendicular to the long axis of the acicular particle. Moreover, the a-axis of them was slightly deviated from the long axis. This crystal structure was not changed by doping of Co2+ and Ti4+ ions.抄録全体を表示PDF形式でダウンロード (5358K) -
武智 弘, 大崎 知恵, 鹿谷 昇, 小田 伸昭, 川崎 宏一1997 年 44 巻 7 号 p. 668-673
発行日: 1997/07/15
公開日: 2009/12/04
ジャーナル フリーThe effect of Mechanical Alloying (MA) process on properties of Ni-Zn soft ferrite was investigated. Raw material powder treated by MA was found to be amorphous structure by using x-ray diffraction and synchrotron radiation analysis. In the case of Ni-Zn soft ferrite treated by MA process, the spinel formation by heating tends to start at 300°C as low as that treated by normal process. The spinel formation in MA treated powder is carried out with a heat generation, which shows a remarkable contrast with that of normal process. MA treated Ni-Zn soft ferrite was found to have higher initial permeability at higher frequency as compared with normal ferrite. It may be attributed to the smaller density after sintering arises from the presence of many micro pores. If a MA treated ferrite with less micro pores and the very fine structure can be obtained, it would be expected to improve the magnetic properties in higher frequency.抄録全体を表示PDF形式でダウンロード (1438K) -
吉川 信一, 藤木 充司, 高橋 昌男, 金丸 文一1997 年 44 巻 7 号 p. 674-677
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーReactive rf-sputter deposition was applied on Fe-Al-N ternary thin film deposition. New wurtzite-type solid solution of Al1-xFexN (x<30atm%) was observed on all as-deposited films. Defect rocked salt-type γ"-FeN coexisted in the films with composition above the solid solution limit. The as-deposited films were paramagnetic. Granular film where α-Fe dispersed in amorphous matrix was obtained by annealing of the films with chemical composition above the solid solution limit in H2 flow at 500°C. They showed soft ferromagnetic behavior. Asdeposited film with composition below the solid solution limit was thermally stable in the annealing at 500°C.抄録全体を表示PDF形式でダウンロード (1414K) -
加藤 哲男, 草加 勝司, 包 于奮, 下条 正隆1997 年 44 巻 7 号 p. 678-685
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーAddition of FeP powder to the sinterd 18Cr-2Mo-2Si-Fe magnetic alloy has been tried to improve its DC and AC magnetic properties. After sintering at 1200°C, DC magnetic property is most improved in 0.15 percent of P content, and DC magnetic property is most improved in 0.20 percent of P content. DC magnetic property increases with the sintering time, but in the initial stage AC magnetic property shows a change of increase and then decrease with time. Improvement of DC magnetic property by addition of FeP powder is attributable to the increase of the grain size and decrease of the porosity with the increase of the sintered density by the liquid phase sintering. On the other hand, enhancement of AC magnetic property may be attributed to the changes of structure originated from the formation of the solid phase of P and a small amount of residual phase accompanying the liquid phase sintering. The process of this structure change has been extensively discussed by the EPMA mapping analysis.抄録全体を表示PDF形式でダウンロード (5898K) -
Takashi Sakamoto1997 年 44 巻 7 号 p. 689-693
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーA small addition of pure nickel powders not only lowers the sintering temperature of Mo but also remarkably increases its sintered density. For example, a 2wt.% addition produces a 94% achieved density even at one-half of the homologous temperature for Mo, the achieved density strongly depending on the sintering temperature. The sintering proceeds quickly with a lower activation energy compared to the Mo bulk diffusion energy, and the entire sintering is accomplished in a rather short period of time.
On the other hand, when Ni-Fe and Ni-Cr alloys powders are respectively added to Mo, each achieved density is greatly increased at a much higher rate too. For example, a 5wt.% (Ni-20 wt.% Fe) powder addition produces 98.5% at 1673K. The sintering temperature on Ni-Fe and Ni-Cr alloys additions is further increased compared to the case of Ni addition. However, the activation energy (129 kJ/mol) for densification on Ni-Fe alloy addition is less and it (206 kJ/mol) on Ni-Cr alloy addition is more than that (143 kJ/mol) obtained by adding Ni.抄録全体を表示PDF形式でダウンロード (249K) -
安 東吉, 崔 徳淳, 川崎 亮, 渡辺 龍三1997 年 44 巻 7 号 p. 694-699
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーThe densification behaviour of TiB2-Fe based cermets during liquid phase sintering in argon was studied in relation to wetting charactertics. The effect of TiB2 powder properties and sintering condition, on the sintering behaviour, were also investigated. It was found that a liquid formed at about 1510K by a pseudobinary eutectic reaction of TiB2-Fe, the liquid formation caused a rapid densification of the compacts. However, a fine TiB2 powder with a high purity showed good sinterability, while coarse and less pure powder showed poor sinterability. Appreciable densification started at the eutectic liquid formation, around 1510K and was kept on up to 1973K to attain full density. The wide temperature range for effective densification, from 1510-1973K, will mean that the rearrangement is dominated by slow process of liquid penetration and extensive wetting. Higher densities were obtained in the TiB2-SUS316L system due to improved wettability associated with the actions of Ni, Cr and Mo. It was found that the liquid penetration and wetting kinetics dominates the densification in the wide temperature range.抄録全体を表示PDF形式でダウンロード (4624K) -
市来 浩一, 浅野 峰生, 川崎 亮, 渡辺 龍三, 宮島 雅史1997 年 44 巻 7 号 p. 700-705
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーMonodisperse spherical particles of Bi-12at%Sb alloy with diameter of 200μm were fabricated by the pul-sated orifice injection method (POIM), in which molten metal is injected from a small orifice by clipping action of a pressure transmitting diaphragm driven by piezoelectric actuater. The Bi-Sb alloy is a candidate material for thermoelectric cooling micr-odevices because of its excellent thermoelectric property at low temperature.
The shape of the obtained particles is spherical with small caps on their surface consisting of Bi phase with negligible Sb content. It has been found that the surface is covered with very thin oxide layer which is less than 100nm as detected by Auger electron spectroscopy. The microstructure is much fmner than that of casted material. The effect of injection atmosphere on microstructural change has been discussed on the basis of cooling rate of molten particle during injection.抄録全体を表示PDF形式でダウンロード (7275K) -
永野 啓, 福永 俊晴, 水谷 宇一郎, 福嶋 喜章, 若山 博昭1997 年 44 巻 7 号 p. 706-711
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーThe crystal structure of graphite is characterized by layers. The large separation (3.35Å between layers compared with the C-C bond length of 1.42Å in the layers indicates relatively feeble binding between the atoms of different layers. Up to date, graphite intercalation compounds with many kinds of atoms and molecules have been reported. In this work mechanical alloying (MA) was employed to synthesize graphite-lithium intercalation compounds. By X-ray diffraction, (002) peak of graphite after MA was observed to be located at lower angle than that before MA. The color of the MA sample was found to become gold. These results revealed that Li atoms were intercalated into graphite layers. Neutron diffraction was carried out to get information of the short range structure around a Li atom. The coordination number of the C-Li correlation for the MA sample with nominal LiC2 composition showed the formation of LiC3.1 intercalation compound, the Li concentration of which is much higher than that of stable LiC6 intercalation compound.抄録全体を表示PDF形式でダウンロード (1914K) -
玉置 昌哉, 冨井 洋一, 山本 直一, 桑原 秀行, 西川 勲1997 年 44 巻 7 号 p. 712-715
発行日: 1997/07/15
公開日: 2009/05/22
ジャーナル フリーThe effect of the gas composition in N2-H2, gas mixture plasma on the growth rate of titanium nitride layers was investigated by optical emission spectroscopy (OES), microscopic observation, and X-ray diffractometry. The growth rate of nitride layers was enhanced by hydrogen addition, which was the highest at 50vol.%N2-50vol.%H2. The results of the spectroscopic measurements and microscopic observations indicate that NH radical intensity is correlated with the growth rate of nitride layers. It is suggested that NH radical plays the most significant role during nitriding process. XRD analysis shows that the compound layers consists of TiN and Ti2N. In the diffusion layers, acicular textures were observed by microscopic observation.抄録全体を表示PDF形式でダウンロード (1990K)
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