巻号一覧
52 巻, 6 号
June
選択された号の論文の13件中1～13を表示しています
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研究
研究
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和田 任弘, 廣 和樹2005 年 52 巻 6 号 p. 399-403
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe tool life in turning of Inconel 718 becomes shorter than that in turning of carbon steel. In order to clarify an effective tool material for the cutting of Inconel 718, the tool wear and the surface roughness were experimentally investigated. The Inconel 718 was turned with WC-Co cemented carbide tool and WC-Ni cemented carbide tool. The main results obtained are as follows: (1) In the WC-Co cemented carbide tools, the wear progress of WC-7%Co cemented carbide tool was slowest. (2) The wear progress of WC-7%Ni cemented carbide tool was slower than that of WC-7%Co cemented carbide tool. (3) In the WC-Ni cemented carbide tools, the wear progress of WC-7%Ni cemented carbide tool was slowest.抄録全体を表示PDF形式でダウンロード (1187K) -
鎌倉 光利, 柴田 英明, 西山 勝廣, 戸梶 惠郎2005 年 52 巻 6 号 p. 404-410
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIn order to improve the mechanical properties of functional Mg alloys, the forming process was investigated using Mg powder mixed with Zr powder. Fine and coarse Mg and Zr powders were used and Zr content was varied from 1 mass% to 20 mass%. Milling time was 7.2 ks and the mixed powders were pressed at a temperature of 573 K and then extruded at an extrusion ratio of 30 at the same temperature. The mechanical properties of the hot-extruded alloys were examined and the effects of powder size and Zr content were discussed. In the hot-extruded Mg-Zr alloys using fine Mg and Zr powders, Zr particles were dispersed uniformly within its microstructure. It was found that the mechanical properties such as Vickers hardness, Young's modulus, bending strength and internal friction increased significantly with increasing Zr content, compared with the hot-extruded Mg material and the hot-extruded Mg-Zr alloys using coarse Mg and Zr powders. Furthermore, such mechanical properties of the hot-extruded Mg-Zr alloys using fine Mg and Zr powders were improved considerably compared with AZ31 wrought alloy, AZ91 casting alloy and the damping casting alloys such as MCM and K1A. Therefore, it was confirmed that the hot-extruded Mg-Zr alloys fabricated in this study has a potential as a structural and functional Mg alloy.抄録全体を表示PDF形式でダウンロード (1708K) -
高畠 進義, 中村 静夫, 大橋 憲太郎2005 年 52 巻 6 号 p. 411-415
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスLaminated TiO2/Fe2O3/ITO and TiO2/Fe2O3/glass films acting under visible light irradiation were prepared by sol-gel processing as well as TiO2/V2O5/ITO or TiO2/WO3/ITO films. Under Xenon lamp irradiation, the rate of bleaching of Methylene Blue (M.B.) on TiO2/Fe2O3/ITO or TiO2/WO3/ITO was found to become greater than that of the original TiO2/glass which was the best under black light irradiation. The TiO2/Fe2O3/glass, whose Fe2O3 was confirmed to be formed as α-hematite by using Mossbauer measurement, seems to be applicable because of its photocatalytic ability.抄録全体を表示PDF形式でダウンロード (654K) -
荻沼 秀樹, 大口 綾子, 大野 さやか, 湯浅 栄二, 沖 善成2005 年 52 巻 6 号 p. 416-422
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスAn aluminum and a zinc powder were mixed to machined chips of AZ31 alloy with various contents, and then the powder mixtures were mechanically alloyed for various milling times using planetary ball mill, for the purpose of recycling of the magnesium alloy. Crystal phase formed in the obtained powder were investigated by X-ray diffraction and Vickers hardness of the powder particles to confirm the formed phases. When Mg-Al system powder mixture was milled for 72 ks by the planetary ball mill, super-saturated solid solution α-Mg and intermetallic compound Mg17Al12 phase are formed, while by milling using the oscillatory ball mill 54 ks was necessary. In the case of mechanically alloyed Mg-2.5 mol% Zn powder, super-saturated α-Mg phase with 2.5 mol% Zn concentration forms. The structures of Mg-28 and 52 mol% Zn powder obtained by the mechanical alloying consist of Mg2Zn2 or MgZn2 and Mg7Zn3 phases and then these phases became amorphous by milling for further time. In the case of mechanical alloying for ternary Mg-Al-Zn system, an icosahedron Mg49(Al,Zn)32 phase, the quasi crystal, forms by the milling for 72 ks in the composition range as following; (30-50)mol% Mg with Al/Zn=(90/10-60/40) molar ratio, Mg-(30-50)mol% Al-20 mol% Zn and Mg-(10-30)mol% Al-40 mol% Zn.抄録全体を表示PDF形式でダウンロード (873K)
研究速報
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Shoichi Nasu, Shinji Nagata, Katsumi Takahiro, Kiichiro Yoshii, Kentar ...2005 年 52 巻 6 号 p. 423-426
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスWe examined the compatibility of lithium titanite (Li2TiO3, tritium breeding materials) fused crystals with nickel (Ni) foils by Rutherford backscattering spectroscopy (RBS) after heat-treatments at 673 K, 773 K and 873 K for 600 min in vacuum (10-6 Pa). An inter diffusion of Ni and titanium (Ti) atoms at 773 K followed a diffusion of a small amount of Ni atoms into the surface of Li2TiO3 at 673 K. At 873 K, Ti and oxygen (O) atoms reached the front surface of the Ni foil and Ni atoms migrated into the Li2TiO3 crystal. In addition, we estimated the diffusion constants at 873 K for Ti and O in Ni.抄録全体を表示PDF形式でダウンロード (2241K) -
—The Effect of Passivation Films—Shoichi Nasu, Shinji Nagata, Kiichiro Yoshii, Katsumi Takahiro, Naoto ...2005 年 52 巻 6 号 p. 427-429
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスWe examined compatibility of sputtered tungsten (W) films with lithium oxide (Li2O, tritium breeding materials) single crystals, the surface of which were passivated by aluminum (Al), silicon (Si) or titanium (Ti) by Rutherford backscattering spectroscopy (RBS). Initial small chemical reactions were observed after heating at 573 K for 1 min in vacuum of 10-6 Pa for each sample. After further heat treatments from 573 K to 723 K there was no additional drastic diffusion.抄録全体を表示PDF形式でダウンロード (1703K)
特集 ネットシェイプおよびニアネットシェイプ
総報
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宮本 大樹2005 年 52 巻 6 号 p. 432
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (92K)
研究
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小林 慶三, 松本 章宏, 尾崎 公洋, 西尾 敏幸, 菊池 光太郎2005 年 52 巻 6 号 p. 433-436
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスTi-20 mass% Ni cermet was near net formed by pulsed current sintering at low temperature. When TiC powder and Ni powder as starting materials were mechanically alloyed for 72 ks, Ni was homogeneously distributed. The obtained mixture was consolidated by a pulsed current sintering using by graphite die and punch. At the heating rate of 100 K/min, the liquid phase of Ni was generated because of the overheating of the punch. The generation of the liquid phase promoted the reaction with the graphite punch and obstructed the densification of a compact. It was effective to increase the ratio of the sectional area of punch to that of die to prevent this phenomenon.
When 37.5 mass% of the TiC powder in the MA was changed into the Ti powder and C powder, a combustion reaction was observed during the pulsed current sintering. This reaction was efficient for the pulsed current sintering to near net forming of TiC-20mass%Ni at a low temperature.抄録全体を表示PDF形式でダウンロード (1134K) -
豊島 寿隆, 志村 辰裕, 渡邉 篤, 大津 秀則2005 年 52 巻 6 号 p. 437-441
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスWe developed the mass production process of 2%Ni-Fe pre-alloyed powder by high-pressure water atomization. When the 2%Ni-Fe pre-alloyed powder was sintered, the sintering characteristics were equal to that of pre-mixed powder of the carbonyl iron and carbonyl nickel, which are conventionally used in powder metallurgy industry. The sintering speed increased as the particle size became finer, so the higher sintering density was obtained even if the sintering temperature was the same. Environmental/sanitary problems and chemical segregation problem, which are inherent in using pre-mixed carbonyl powders, will be solved by adopting the pre-alloyed powder for the production of MIM parts. As a result, it can be expected that the MIM market will be much more expanded.抄録全体を表示PDF形式でダウンロード (1570K)
解説
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津守 不二夫2005 年 52 巻 6 号 p. 442-445
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスA new powder compaction process named “Bingham semi-solid/fluid Isostatic Pressing (BIP)” is proposed and developed to fabricate green compact with complicated shapes. Conventional processes such as die pressing or CIP (cold isostatic pressing) process, are encountered two technical problems: inhomogeneous density distribution in powder compact and breakage of products during unloading process. The present process, where a semi-solid mold works also as a pressurizing medium, can overcome such problems. Yield stress of the mold is much lower than process pressure for BIP, so that the mold behaves like a liquid that applies isostatic pressure to the powder. This behavior of the fluid mold prevents the damage of powder compact during the unloading process. Finally, it is demonstrated that complicated powder compacts are fabricated by this process.抄録全体を表示PDF形式でダウンロード (913K)
研究
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Janghwan Oh, Atsushi Kakitsuji2005 年 52 巻 6 号 p. 446-452
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスA new isostatic pressing method named “Bingham semi-solid/fluid Isostatic Pressing (BIP)” has been developed in which Bignham semi-solid/fluid material is employed as a mold material to form a green body with complicated shape without the crack due to the spring-back of a rubber mold. In this paper, a few parameters of BIP process that influence the dimensional accuracy of a green body were investigated.
The soaking with wax to the green body associated with applied pressure, powder size and the ratio of mold thickness-to-width was examined. Mixing the powders with different diameter and increasing the packing density could prevent the soaking. To get the green body with desired shape, the relation between the thickness of a mold and the dimensional accuracy was investigated. Granulated powder and non-granulated powder were compared to investigate their effect on the dimensional accuracy of a green body. Granulated powder was more effective than non-granulated powder.抄録全体を表示PDF形式でダウンロード (2172K) -
津守 不二夫, 原 康洋, 安富 亮太, 島 進2005 年 52 巻 6 号 p. 453-457
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIt is extremely difficult to fabricate thin plate parts by conventional powder metallurgy processes using dry powder; uni-axial pressing results in inhomogeneous density distribution, which causes distortion or breakage of sintered products; isostatic pressing, which could make compacts with homogeneous density distribution, also encounters serious problems such as breakage due to tensile stress at the surface of powder compacts by rubber mold during unloading process. In this study, newly developed Bingham Semi-solid/fluid Isostatic Pressing (BIP) process is employed to overcome these problems. For demonstration, an attempt is made to fabricate simple disks and wavy sheets with about some hundreds micrometer thickness. We also develop and perform an FEM simulation to investigate deformation patterns and density distribution in powder compact during the process, and compare with experimental results.抄録全体を表示PDF形式でダウンロード (1338K) -
津守 不二夫, 栗原 史和, 小寺 秀俊, 島 進2005 年 52 巻 6 号 p. 458-463
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスNd-Fe-B magnet, which possesses the highest magnetic performance, is fabricated by powder metallurgy process. The magnetic powder is compacted under an applied magnetic field for the particles' easy directions of magnetization to be oriented along the magnetic flux. It is widely known that the magnetic powder flows and moves during this process both by the applied magnetic field and by the applied pressure. Since this process determines the final properties of the magnet, it is of great importance to clarify the behavior of the powder during the process.
In the present study, we focus on the flow behavior of Nd-Fe-B powder due to an applied magnetic field. An attempt is made to make clear the powder flow by in-situ observation with a transparent die set. An FEM-DEM simulation is also performed to investigate the flow of magnetic flux that affects the movement of the powder. It is thereby shown that simulated results of the flow of magnetic powder and change of the structure built-up by particles are in good agreement with experimentally derived ones.抄録全体を表示PDF形式でダウンロード (1882K)
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