巻号一覧
47 巻, 6 号
選択された号の論文の17件中1～17を表示しています
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Koichi Yanai, Mutsumi Hirai2000 年 47 巻 6 号 p. 591-599
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーAl2O3 powders were compacted by uniaxial dry pressing to evaluate the relationship between tensile strengths of green pellets and their powder packing structure. For green pellets which do not include undestroyed hard agglomerates, their tensile strengths were described using the primary particle size of the powder, porosity and median pore size normalized by the particle size of the green pellets. The pore size in green pellets of powders having a sphere-like shape was relatively small, which resulted in their larger tensile strengths. The tensile strengths of slugged powders decreased with increasing ratio of the strength of agglomerates prepared by the slugging treatment to the compaction pressure.抄録全体を表示PDF形式でダウンロード (570K) -
Kazuhiko Tanaka, Koji Hayashi2000 年 47 巻 6 号 p. 600-606
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーFe green and sintered compacts with relative densities of about 70-90% and with size of mainly 3.2×12×15mm3 were nitrided by heating in NH3+H2 (1:1) flowing mixed gas at 923 K for 3.6-14.4ks. These two kinds of compacts could be almost completely nitrided to Fe4N by heating for 14.4ks. The relative densities of nitrided compacts, however, were 76-77% which were lower than those before nitriding. This was because the linear expansion up to about 11-12 % for green compact and 6-7% for sintered compact occured mainly due to crack generation. The saturation magnetizaion of two kinds of nitrided compacts were both about 170-175 emu/g, which was about 80% of the value of Fe solid.抄録全体を表示PDF形式でダウンロード (6379K) -
有賀 敦, 小澤 真一郎, 川村 和郎2000 年 47 巻 6 号 p. 607-613
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーBoron and titanium carbides were synthesized by the carbothermic reduction of boron or titanium oxides dispersed in a cure resin. On raising heat treatment temperature (HTT), the metal oxides were reduced and reacted with the resin carbon produced from resin, and also the resin carbon was graphitized partly by the presence of metal oxides. When the cure resin containing 65 or 70wt% TiO2 was fired at 2000 and 2250°C, a porous sintered TiC was produced. The sintering bodies with addition of 70 wt% TiO2 showed specific surface area of 240 m2/g (HTT: 2250 °C), the bending strength of 70MPa (HTT: 2000°C), and the specific resistance of 2×10-4Ωcm (HTT: 2250°C).抄録全体を表示PDF形式でダウンロード (4588K) -
加藤 清隆, 増井 孝実2000 年 47 巻 6 号 p. 614-618
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーThe B2 FeAl (Fe-40Al and Fe-48Al (at.%)) sintered compacts were prepared by metal injection molding (MIM) process. Then, tensile tests were performed in air at room temperature, 400°C, 600°C and 800°C. The results obtained were summarized as follows.
(1) The Fe-48Al compact had the good 0.2% proof stress and tensile strength more than 600 MPa at room temperature. However, they rapidly decreased with increasing test temperature. On the other hand, the 0.2% proof stress of Fe-40Al compact at 400°C and 600°C were almost equal to that at room temperature (-300 MPa). The tensile strength of this compact showed the maximum (680MPa) at 400°C. The tensile strength of both compacts went down to less than 100 MPa at 800°C.
(2) At room temperature, the Fe-40Al compact showed the substantial elongation of 2.3%, while that of Fe-48Al compact was only 0.3 %. The elongation of both compacts at 600°C showed high value of 25-30 %. Both compacts changed the fracture mode from brittle to ductile at the temperature range from 400°C to 600°C.抄録全体を表示PDF形式でダウンロード (4404K) -
勝山 茂, 吉岡 大貴, 井藤 幹夫, 真島 一彦, 永井 宏2000 年 47 巻 6 号 p. 619-624
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーWe have prepared Zn1-xAlxO ceramics by the polymerized complex method and examined the microscopic structure and thermoelectric properties comparing with the results of the sample prepared by the solid state reaction method. A small amount of ZnAl2O4 spinel phase which increases with increasing x was observed in the hot-pressed samples with x ≥ 0.02 by x-ray diffraction and SEM. The grain size of the sample by the polymerized complex method is much smaller than that of the sample by the solid state reaction method. The electrical resistivity and the absolute value of the Seebeck coefficient for the sample by the polymerized complex method are smaller than those for the sample by the solid state reaction method. The carrier contribution to the thermal conductivity of the sample by the polymerized complex method is larger than that of the sample by the solid state reaction method in the whole temperature range, while the phonon contribution to the thermal conductivity at low temperature of the sample by the polymerized complex method is smaller than that of the sample by the solid state reaction method. These behaviors are ascribed to the difference of the carrier concentration and the grain size between these samples.抄録全体を表示PDF形式でダウンロード (3012K) -
岩津 修2000 年 47 巻 6 号 p. 626
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (73K) -
守吉 佑介, 清水 禎樹, 渡辺 隆行2000 年 47 巻 6 号 p. 627-635
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーB-C-N nanotubes prepared by a plasma evaporation method were characterized by a transmission-electron microscopy (TEM) and an electron-energy-loss spectroscopy (EELS). The nanotubes obtained were divided into three types of carbon-, boron nitride-, and combined nanotubes of boron nitride with carbon. However, BCXN nanotubes of homogeneous phase could not be obtained. This indicated that a stable phase in the experimental condition was in the mixtures of carbon and boron nitride rather than in a homogeneous phase of BCXN compounds. Also the effect of temperatures on the formation of nanotubes was studied. Resultantly it was shown that nanotubes were formed at higher temperatures than 3000 K and, on the other hand, nanocapsules were formed at lower temperatures than 3000 K. Based on the microstructural data obtained, the formation mechanisms of both nanotubes and nanocapsules were described.抄録全体を表示PDF形式でダウンロード (11906K) -
小林 慶三, 松本 章宏, 尾崎 公洋, 杉山 明, 本田 義彦2000 年 47 巻 6 号 p. 636-640
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーTi-20at%Fe, Ti-30at%Fe and Ti-40at%Fe synthesized by cold crucible levitation melting process were investigated on the changes of constructional phases against milling time during the mechanically grinding (MG) process. The recovery ratio of mechanically ground powders were over 70% by weight. Little amorphous phase were produced by the MG process of Ti-Fe binary system.
In order to synthesize amorphous phase, the MG of Ti-40at%Fe alloy which included boron and/or silicon were carried out. Though 5at%Si addition was effective to produce a lot of amorphous phase by the MG for 90 ks, it was promoted a recrystalization of the amorphous phases by over 90ks milling. When 5at%B was added to Ti-40at%Fe, the amorphous phase increased according to incrementation of milling time of the MG. However, a long time milling was needed to generate a lot of amorphous phase. As for the Ti-35at%Fe-5at%Si-5at%B alloy, even a short milling time was able to generate a lot of amorphous phases.抄録全体を表示PDF形式でダウンロード (386K) -
小林 慶三, 西尾 敏幸, 杉山 明, 松本 章宏, 尾崎 公洋2000 年 47 巻 6 号 p. 641-644
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーMg-10mass%Be, Mg-20mass%Be, Mg-30mass%aBe and Mg-40mass%Be alloys were synthesized by mechanical alloying (MA) of elementary Mg and Be powders for 720 ks milling under 66 kPa argon gas atmosphere using by a planetary ball milling. In the case of Mg-10mass%Be, the big blocks occurred due to the joining of the MA powders. Others showed fine powders after the MA process. Mg was able to compound 10mass%Be by the MA process safely. In the obtained Mg-10mass%Be block, Be particles dispersed in the Mg matrix uniformly and had no reaction with Mg.
Mg-10mass%Be alloy synthesized by the MA was consolidated by pulsed current sintering at 673 K for 0.5 ks under a pressure of 196MPa. The sintered body was a composite material including homogeneous Be particles and showed a hardness of 68HV.抄録全体を表示PDF形式でダウンロード (5942K) -
鰐部 吉基2000 年 47 巻 6 号 p. 646
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (88K) -
古谷 圭一2000 年 47 巻 6 号 p. 647-652
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーParticle matters have their unique physical features in contrast with solid, liquid and gaseous materials. They are mixtures of particles with various states of solid; mono-, aggregated and coagulated particles. Each particle has its own surface and bulk composition and distribution of size and composition. The idea of characterization with which its property can be reproduced is explained. Examples of bulk compositional analyses, effective pre-treatments, microprobe analyses and in-situ analysis are introduced.抄録全体を表示PDF形式でダウンロード (1769K) -
桜井 法昭, 武川 淳二郎2000 年 47 巻 6 号 p. 653-657
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーIn order to obtain Ti-Mo alloy having high density and strength by sintering at a temperature as low as possible, the enhancing effects of the intermediate cold isostatic pressing (CIP) on these properties in MIM process were investigated.
A Ti-12Mo alloy, in which the β phase is stable, was selected as test material because of its high corrosion resistance and strength.
In this work, the debound compacts of Ti-12mass%Mo premixed powder were CIPed after the pre-sintering (heating at the temperature under 900°C).
It was shown that the intermediate CIP treatment was much effective in increasing density; i.e., the relative density of sintered compacts was risen more than 10% by this treatment. And the tensile strengths were also increased, because high density was available by sintering at the lower temperature where no severe grain growth occurred. It was also shown that the density and strength of Ti-12Mo compacts increased with decreasing the pre-sintering temperature.抄録全体を表示PDF形式でダウンロード (4288K) -
鎌倉 光利, 柴田 英明, 赤塚 久修, 疋田 寿久, 高坂 槇治2000 年 47 巻 6 号 p. 658-664
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーThe key to form uniform and high-density green compacts perfectly is based on the raw material powders themselves and the overall powder compacting process. First of all, the blended powders must have enough pressing flowability. In another word, the powders must be well-flown in a complex die cavity when the powder filling is carried out. Therefore some preliminary studies on the raw material powders were worked out and one of the appropriate blended powder for pressing flowability was confirmed. Second, the practical powder compacting process was studied by the new CNC press. This includes powder filling, powder transfer, compressing and ejection process. During the whole compacting process, the compressing motion timing, positioning, compacting pressure, ejection speed and holding force in ejection of the each upper, lower and side punch are carefully monitored. Finally, the proper powder compacting process by the new CNC press, which was enough consistent and accurate, was established after evaluating green compacts in terms of density, density distribution, forming accuracy and so on.抄録全体を表示PDF形式でダウンロード (5350K) -
藤木 章2000 年 47 巻 6 号 p. 666
発行日: 2000/06/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (94K) -
小野 秀昭, 島田 宗勝, 藤木 章, 山元 洋, 園田 雅之, 谷 雅人2000 年 47 巻 6 号 p. 667-673
発行日: 2000/06/15
公開日: 2010/11/19
ジャーナル フリーBulk exchange-spring magnets of Nd11Fe72Co8V1.5B7.5 and Nd9Fe76Co8V16B alloys were prepared by Spark Plasma Sintering (SPS) using the rapidly quenched ribbon powders. The effects of SPS process conditions on magnetic properties and structures were investigated. SPS is a type of solid compression sintering similar to hot-pressing (HP) and can be performed at lower temperature with a shorter holding time. Bulk magnets reached to approximately full density at a sintering temperature of higher than 650°C for 5 min. and had magnetically isotropic properties. They indicated the spring back phenomenon peculiar to exchange-spring magnets and consisted of multiphase of the Nd2Fe14B type phase and the α-Fe type phase. Grain growth did not occurred between the powders of the starting ribbons, but the fine crystals were observed inner the powders of the ribbons with an increase in the sintering temperature.
Optimum preparation conditions and magnetic properties were as follows: composition, Nd9Fe76Co8V1B6; surface velocity of the roller during melt spinning for starting ribbons, Vs=20 m/s; SPS condition, at 675°C for 5 min. under 490 MPa; magnetic and other properties, Br=0.99 T, Hcj=415 kA/m, (BH)max=107.8 kJ/m3, Hk/HcJ×100=23%, spring back ratio=40% and D=7.59 Mg/m3.抄録全体を表示PDF形式でダウンロード (4452K) -
厳 泰永, 小林 義政, 裘 進浩, 谷 順二, 高橋 弘文2000 年 47 巻 6 号 p. 674-680
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーThe present study aims to fabricate PZT piezoelectric ceramic sheets which perform at a high capacity in low electric fields for developing actuators with large displacement. This paper describes the fabrication procedures of PZT sheets and their results. As the results of XRD analysis and SEM observations of precalcined powders showed, 800°C was the appropriate calcination temperature for Pb(Zr0.3Ti0.7)O3 and Pb(Zr0.65Tia0.35)O3 composition. Green sheets with uniform thickness distribution were fabricated by Doctor Blade process with slurries 2000-5000cp in viscosity. The size of the fabricated green sheets was 135±5μm and 50±2μm in thickness, 180mm in width, and 5m in length, with a density of 4.7-5.1 g/cm3. Additives, such as solvent, binder, plasticizer and dispersant were completely eliminated by heat treatment at 500°C. The PbO excess atmosphere sintering at 1000°C produced PZT sheets which have perovskite phases only, and were well densed.抄録全体を表示PDF形式でダウンロード (3917K) -
松田 光弘, 三浦 秀士2000 年 47 巻 6 号 p. 681-685
発行日: 2000/06/15
公開日: 2009/12/04
ジャーナル フリーIn our previous studies on the 4600 steels produced by Metal Injection Molding (MIM) process using mixed elemental powder, the fine heterogeneous microstructure caused by the agglomeration of Ni powders was reported to be significantly effective for the improvement of mechanical properties. This study has been performed to clarify and optimize the relationship between the mechanical properties and the heterogeneous microstructure for ultrahigh strengthening the sintered low alloy steels (4600grade, 0.4 mass%C) produced by MIM process varying Ni content from 0 to 8 mass%.
The tensile and fatigue strength were improved significantly with increasing Ni content to 6mass%, without loss of the ductility. This seemed to be due to the solution strengthening and the mezzo-heterogeneous microstructure which were consisted of Ni rich martensite surrounded by a network of tempered martensite. However, the tensile and fatigue strength of the steel added 8 mass% Ni were dropped by the increase of retained austenite.抄録全体を表示PDF形式でダウンロード (2157K)
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