巻号一覧
53 巻, 11 号
November
選択された号の論文の10件中1～10を表示しています
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研究
受賞記念講演
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—低温での内部酸化/内部窒化についての基礎研究から応用研究への展開—高田 潤2006 年 53 巻 11 号 p. 841-848
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスSystematic studies on internal oxidation/nitriding of alloys at low temperatures have not been reported in contrast to high temperature oxidation/nitriding reported so far. However, the oxidation/nitriding at low temperatures has great advantages on discussion of the diffusion process of dissolved oxygen in α-Fe and the formation of nanoparticles of oxide/nitride which effects upon various properties of the alloys.
In this paper, characteristics and mechanism of internal oxidation/nitriding behavior are explained. Next the determination of oxygen diffusion coefficient in α-Fe by using internal oxidation of three different alloys is introduced on the basis of the oxidation rate equation and the thermodynamic data. Furthermore the development of novel Mo alloys having high ductility and high strength due to microstructure controlling by distribution of small nitride particles through a new multi-step nitriding method is also described.抄録全体を表示PDF形式でダウンロード (1538K)
研究
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王 新敏, 井上 明久2006 年 53 巻 11 号 p. 849-855
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスIn this technique, gas-atomization was used at the first stage to produce alloy powders with molten metal. subsequently the atomized alloy powders are flown down, and then crushed into a vapidly notating disk with a high speed of about 250 m/s. Non-solidified and half solidified alloy powders were broken to the smaller ones. According to this mechanism, the further subsequent crash is likely to occur for the remaining non-solidified and half solidified alloy powders.
This non-solidified and half solidified alloy powders can be broken to fine powders one by through the multistage crush mechanism.
In this method, the size of fine powders could be controlled by changing the temperature and flux of molten metal, flux of gas, tangential velocity of rotating disk, distance between disk and nozzle for molten metal, flux of cooling media, and so on. Furthermore, the powders are flown and rotated simultaneously by the rapidly circumrotating disk, The unique mechanism rsuets in the production of spherical powders. In the case of producing Cu powders. The first stage gas atomization, 40μm diameter powders are obtained by the first stage second crush on the rapidly circumrotating disk can produce 10μm powders. Similarly, We also confirmed the production of fine 7μm Al powders. These fine spherical powders, can have various nonequilibrium phases such as nano-crystalline and amorphous phases owing to high cooling rates.抄録全体を表示PDF形式でダウンロード (995K)
研究速報
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一色 康博, 獨古 薫, 金村 聖志2006 年 53 巻 11 号 p. 856-859
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスFine particles of Li+ ion conductive material Li1.5Al0.5Ti1.5(PO4)3 were prepared by sol-gel method. Using prepared Li1.5Al0.5Ti1.5(PO4)3 particles, three dimensionally ordered macroporous membranes of Li1.5Al0.5Ti1.5(PO4)3 were prepared by colloidal crystal templating method. Colloidal crystal composed of mono-disperse polystyrene particles (3.0μm diameter) was utilized as a template. Three-dimensionally ordered composite membrane were prepared by filtrating polystyrene particles and Li1.5Al0.5Ti1.5(PO4)3 particles. Polystyrene particles were removed by calcinations at high temperature, and then macroporous Li1.5Al0.5Ti1.5(PO4)3 was obtained. Li+ ion conductivity of prepared macroporous Li1.5Al0.5Ti1.5(PO4)3 membrane annealed at 950°C for 12 hour, was 5.3×10−5 S cm−1 at room temperature.抄録全体を表示PDF形式でダウンロード (619K)
研究
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松村 忠朗, 今西 誠之, 平野 敦, 菅野 了次, 武田 保雄2006 年 53 巻 11 号 p. 860-864
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスNaxFeO2 was obtained by chemical oxidization method using NO2BF4 and Br2 which shows the redox potential of ca. 5.1 V and ca. 4.1 V vs Li/Li+, respectively. The oxidized products showed different X-ray diffraction patterns depending on the oxidizing species. In case of NO2BF4, as soaking time progressed, new phase increased with decreasing of NaFeO2 as stating material. The oxidized NaxFeO2 was possible to be inserted the Li ion electrochemically, and resulted in the crystal structure similar to the layered LiFeO2 synthesized by the Li-ion-exchange method from NaFeO2. Reversible discharge-charge reactions were progressed for NaxFeO2 // Li cell, and ac. 150-200 mAh/g of initial capacities were achieved although the capacities decreased with cycle numbers.抄録全体を表示PDF形式でダウンロード (510K)
特集：HIP/CIPおよび関連技術
総報
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藤川 隆男2006 年 53 巻 11 号 p. 866
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスPDF形式でダウンロード (134K)
総説
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藤川 隆男2006 年 53 巻 11 号 p. 867-875
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスFifty years have passed since the HIP process was invented and it has now become an indispensable process for the manufacture of some high-value added products like jet engine turbine blades and ceramic ball bearings. In Europe and US, HIP units have been getting larger and larger due to the demands for processing larger components and reducing processing cost, and most HIP treatments are now being carried out in toll HIPing companies on a subcontract basis. In Japan, rejuvenation of turbine blades for industrial gas turbines has been carried out and super-conductor cables made of oxide ceramics are processed in the oxygen partial pressure controlled atmosphere by using a special high pressure gas furnace like a HIP unit. Large projects related to the next generation commercial jet plane, B787 and ITER nuclear fusion reactor have now set out and HIP treatment is expected to play important roles in these projects in the coming decade.抄録全体を表示PDF形式でダウンロード (1599K)
研究
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岡田 泰行, 林 秀考, 岸本 昭2006 年 53 巻 11 号 p. 876-879
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスEvaluation samples of α-silicon carbide ceramics were first fabricated by glass capsule HIP method using powder mixture of silicon carbide and aluminum nitride with various ratio. The resultant aluminum nitride added silicon carbide ceramics were doped with nitrogen by changing the post-HIP nitrogen gas pressure. The lattice parameter increased with the amount of adding aluminum nitride indicating that the incorporated aluminum substituted smaller silicon atoms. After post-HIP treatment, lattice parameter then decreased with nitrogen gas pressure. The piezoresistive coefficient increased with the addition of aluminum nitride, it further increased with the nitrogen doping pressure.抄録全体を表示PDF形式でダウンロード (446K) -
津守 不二夫2006 年 53 巻 11 号 p. 880-884
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスBingham semi solid/fluid isostatic pressing (BIP) was developed recently by the author. Advantages of this method are as follows: cracks in powder compacts that are likely to occur because of the mold's springback at the time of unloading can be avoided; the density is almost uniform in the products. On the other hand, it is not easy to form the mold of a complicated structure from wax or the semi solid material, which is of a small yield stress. Accordingly, wax with a higher yield stress is needed. However, this easily induces cracks in the mold itself as well as in the compacts. In this research, therefore a new process, named "the Temperature Controlled BIP" is developed, and the characteristics of this new process are discussed. In this process, we first form a mold by wax of a higher yield stress, and we then raise the temperature of the mold to decrease its yield stress before pressing. We liquefy the mold completely by raising the temperature before unloading and take out the compact.抄録全体を表示PDF形式でダウンロード (584K) -
津守 不二夫, 池内 駿介2006 年 53 巻 11 号 p. 885-888
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスNew powder compaction process using a Bingham semi-solid/fluid mold was developed to fabricate micro parts. In the present work, a powder material was filled as slurry in a solid wax mold, dried and compressed by conventional pressing methods, such as isostatic pressing or die compaction. It is important to use slurry for filling because dry powder is hard to fill in the micro cavity. It is also essential to control the process temperature to treat micro parts. The wax mold was heated during compaction and became semi-solid state, which could acts as a pressurized medium for isostatic compaction. Since the compacted micro parts were very fragile, the mold's temperature was controlled to higher than its melting point during unloading, to avoid breakage of the compacts. To demonstrate effectiveness of the present process, some micro compacts of alumina are shown as examples.抄録全体を表示PDF形式でダウンロード (575K) -
杵鞭 義明, 石黒 裕之, 内村 勝次, 渡利 広司2006 年 53 巻 11 号 p. 889-893
発行日: 2006年
公開日: 2007/02/28
ジャーナル オープンアクセスInternal gas pressure in layered green sheets during binder burnout has been focused on in terms of heating rate. Microstructure observation revealed that the defect arose at the temperature where the decomposition rate of binder reached maximum, and severe defects formed at high heating rate. These results suggest that the defect formation originated in the decomposed gas passing through the finely porous structure, i.e. internal gas pressure. Thus the external compressive pressure upon green bodies should suppress the defect formation, which was demonstrated by the pressure generated via centrifugal force. Then the pressure balance between the internal gas pressure and a green strength assisted by centrifugal force was analyzed based on gas flow kinetics, which revealed the quantitative aspects of internal gas pressure as a function of a heating rate and the size of green body.抄録全体を表示PDF形式でダウンロード (648K)
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