巻号一覧
57 巻, 12 号
December
選択された号の論文の16件中1～16を表示しています
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研究
研究
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和久 芳春, 岩本 祥希, 吉延 匡弘, 春井 眞二, 磯部 景一2010 年 57 巻 12 号 p. 747-752
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスThe flake-forming behavior of Ni-Cr alloy powders during a wet ball milling process and the effect of volume percent of flaky Ni-Cr alloy particles on three-point flexural strength and fracture toughness of clay tile composites reinforced with flaky Ni-Cr alloy particles have been investigated. The flexural strength and fracture toughness of composites can be simultaneously improved by increasing the volume percent of flaky Ni-Cr alloy particles. The SEM observations indicates that the improvement in fracture toughness may be attributed to plastic deformation of flaky Ni-Cr alloy particles at crack tip. Fabricating composites reinforced with flaky Ni-Cr alloy particles is an effective toughening technique capable of simultaneously improving the strength and toughness of brittle materials by utilizing plastic deformation of ductile phase. The volume resistance of the clay tile/30%flaky Ni-Cr alloy particle composites is 7.5×10-2 Ω·cm, which is larger than that of Ni-Cr (JIS NCH-1) (1.1×10-4 Ω·cm). The resistance temperature coefficient of the composite is almost the same as that of Ni-Cr (JIS NCH-1). The composite is therefore promising candidate as resistance materials.抄録全体を表示PDF形式でダウンロード (1732K)
研究速報
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宮下 耕平, 林 大和, 滝澤 博胤2010 年 57 巻 12 号 p. 753-757
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスTiN coating was successfully formed by burying a quartz glass substrate into Ti powder and subsequent microwave irradiation in air. The temperature of the powder rapidly rose up to 1100°C by microwave irradiation, and TiN coating was formed on the substrate by vapor phase reaction. Particle size, film thickness, and Vicker's hardness of the coating increased with increasing the irradiation time and microwave power. Similar technique was also applied to form TiCN coating by using mixture of Ti and carbon powder instead of Ti powder. It was revealed that the carbon content, film thickness, and Vicker's hardness of the coating increased with increasing the carbon content in the starting powder.抄録全体を表示PDF形式でダウンロード (919K)
研究
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澤田 俊之, 柳本 勝2010 年 57 巻 12 号 p. 758-763
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスEffects of B content and heat treatment on properties of gas atomized powders with Ni-10mass%Cr-36mass%Mo-Xmass%B compositions (X=1.5∼4) were investigated. Examined powders were produced by gas atomization, followed by sieving under 150 μm. These powders were heat treated at various temperatures to investigate the effect of heat treatment temperature.
As a result, tetragonal M3B2, tetragonal M5B3 and orthorhombic M3B2 type complex borides were observed in examined powders before and after the heat treatment. Compositions and crystal structures of complex borides varied depending on B contents in examined powders, hereby compositions of Ni-based matrix phases also varied. Vickers hardness after the heat treatment at 1473 K increased with increasing B content.抄録全体を表示PDF形式でダウンロード (1371K) -
松本 章宏, 加藤 清隆, 下島 康嗣, 細川 裕之, 高田 真之, 平松 隆2010 年 57 巻 12 号 p. 764-768
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスWC-25vol%FeAl compacts have been prepared using wet milling and the subsequent pulse current sintering. Powder mixtures consisting of (1) WC, Fe-40at%Al and (2) WC, Fe, Al powders have been mixed to give the desired composition of WC-25vol%FeAl. They have been milled using a cylindrical ball mill with ethanol. Milled powders have been dried at room temperature and consolidated using pulse current sintering method at 1273 K in vacuum. The compacts thus obtained have had fine and homogeneous structure. Vickers hardness of both compacts has increased with increasing milling time. Transverse rupture strength of the former compact has increased with increasing milling time, but that of the latter one abruptly decreased. This is due to the formation of Fe3W3C and Al-O phase.抄録全体を表示PDF形式でダウンロード (1507K)
解説
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木村 博2010 年 57 巻 12 号 p. 769-778
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスThis article describes a study of intelligent nanosintering, as the author here use this term, by which one can provide a platform for the bulk nanocrystalline synthesis using multi-variable controled thermo-mechanical processing equipped with pulse electric current and microwave heating. Emphasis is firstly placed on the set-up of the phenomenology of electric field assisted densification during heating of the amorphous ceramic powder by varying manipulating variables of electric current, compact height and millimeter wave radiation power. In the case of amorphous and/or nanocrystalline ZrO2-Al2O3, the rate of densification enhanced under electric field (E) is expressed on the basis of an Arrhenius-type equation of Newtonian viscous flow, ηp = ηp0(E) esp{Q(E)/kT}, having a decreased value of the apparent activation energy (H). Then, within the framework of sintering route map up to full-density, the optimal condition for in process nonequilibrium structure control densification is provided with the reference to constitutive equations for densification during viscous flow and/or superplastic flow and the master sintering curve for densification accompanying grain growth. Moreover, it is evidenced that a variety of nanosintering techniques makes it possible to synthesize fully densified samples of amorphous B4C, nanocrystalline cubic and tetragonal (ZrO2-3mol%Y2O3)80(Al2O3)20 using nanomechanochemically synthesized amorphous powders.抄録全体を表示PDF形式でダウンロード (1931K)
研究
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遠山 武範, 齊藤 高志, 島川 祐一2010 年 57 巻 12 号 p. 779-785
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスWe evaluated structural stabilities for A-site-ordered perovskites using the computer program "SPuDS", and succeeded in synthesizing designed AMn3Al4O12 (A=Y, Dy) under high-pressure and high-temperature conditions. Bond Valence Sum calculations with the refined structural parameters revealed that the compounds are represented as ionic A3+Mn3+3Al3+4O2-12. Mn3+ ions at the A' site produce high-spin magnetic moments and they align antiferromagnetically. The A-site Dy spins, on the other hand, behave paramagnetically and show no correlation with the A'-site Mn spins. The antiferromagnetism of the A'-site Mn spins is caused by the nearest neighboring Mn-Mn direct exchange interaction.抄録全体を表示PDF形式でダウンロード (1172K)
特集：永久磁石材料とその応用
総報
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山元 洋2010 年 57 巻 12 号 p. 788
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (112K)
研究
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高田 幸生, 福本 恵紀, 金子 裕治, 真鍋 明, 宮本 典孝, 今田 真, 菅 滋正2010 年 57 巻 12 号 p. 789-794
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスEffects of Dy-diffusion treatment to Nd-Fe-B sintered magnets on those microstructure and coercivity were investigated. Coercivity of magnets increases in proportion with raising temperature of Dy-diffusion treatment and keeping longer term. As a result, it is found that changes of coercivity by this treatment can be classified into 2 modes: 1st step shows a rapid increase in coercivity where Dy diffuses into grain boundary and surrounds grains. 2nd step is a gradual increase in coercivity where Dy diffuses into 2-14-1 phases. As an extending study, we have tried to observe the magnetic domains of Nd-Fe-B sintered magnets by using XMCD-PEEM technique. It is found that Dy diffusion treatment suppresses the generation and the growth of magnetic reversed domains as same as Dy-doping into Nd-Fe-B magnets.抄録全体を表示PDF形式でダウンロード (1679K) -
—トルクリミッタ用ロータ材料の開発—山元 洋, かじ川 淳朗2010 年 57 巻 12 号 p. 795-800
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスThis research aimed at the development of the rotor material for torque limiter. The coercivity of the rotor material is required to be around 80 kA/m. The melt-spun ribbons of Pr-Fe-Co-Ti-B system alloys were prepared by single roller liquid-quenching method. The effect of composition, wheel velocity and heat treatment on the magnetic properties were investigated. The optimum preparation conditions and some of properties were follows: composition, Pr3.5Fe80.5Co8Ti1B7, wheel velocity, 30.0 m/s; heat treatment condition, 675°C for 5 min in Ar atmosphere; magnetic properties were follows; (BH)max=41.4 kJ/m3, HcJ=85.2 kA/m3, Jr=1.39 T, α(Jr)ave=0.01 %/°C (reversible). The value of (BH)max for the isotropic compression molding Pr3.5Fe80.5Co8Ti1B7 bonded magnet prepared by using the ribbons heated at 675°C for 5 min is 10.1 kJ/m3, HcJ=83.4 kA/m3, Jr=0.535 T, and the density is 5.60 Mg/m3.抄録全体を表示PDF形式でダウンロード (787K)
受賞記念講演
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平塚 信之2010 年 57 巻 12 号 p. 801-808
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスThe substitution of elements was carried out to improve the soft magnetic properties in hexagonal ferrites. A series of Ba3Co2RxFe24-xO41 samples (R=La, Nd, Gd, Dy, Ho, Yb) with Z-type structure were made. The initial permeability of Gd3+-substituted sample (x=0.1) was the highest of all samples, because the apparent specific anisotropy field of the sample was the lowest. The substituted sample Ba3Co2Mn0.5xTi0.5xFe24-xO41 with x=0.4 had the maximum μ' of 25.7 and μ' × fr product of 17.6 GHz. The M-T curve showed an anomalous drop below the Curie temperature, which reflected the change from in-plane magnetic anisotropy to vertical one with increasing temperature. BaCoxTixFe12-2xO19 (x=1-3) were prepared. The initial permeability increased to 27 for a sample with x=1.15. The reason for this may be that the coercivity becomes small as a result of the decrease in the anisotropic magnetic field. SrCo2+yMe4+yFe12-2yO19 (Me=Zr, Hf) samples were also fabricated. For SrCoyZryFe12-2yO19 (y=0-1.2), magnetization increased slightly for the sample of y=0.4, and then decreased with increasing y. Coercivity drastically decreased up to y=1.2. Magnetic behavior of the Co-Hf substituted sample was similar to that of the Co-Zr substituted one.抄録全体を表示PDF形式でダウンロード (1790K)
研究
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保坂 伸幸, 神島 謙二, 柿崎 浩一, 平塚 信之2010 年 57 巻 12 号 p. 809-813
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスThe conventional synthesis of ferrite compounds consists of two-steps sintering processes. The first process is calcination to produce precursor of a desired ceramic object, and the second is to obtain the desired object.
However, it was difficult to prepare X-type hexaferrite (Ba2Me2+2Fe28O46: Me2X, Me=Co, Ni, Cu, Zn) samples by this method. Two-steps sintering of these samples resulted in formation of spinel, M and W-type ferrite phases.
We have found that Me2X can be obtained by a one-step sintering method that skipped the calcination process. When this method is applied, the temperature range of Me2X formation was very narrow and about 1250°C.
We measured the saturation magnetization at 2 K and room temperature, and examined the Curie temperatures of Me2X samples produced by this method. These magnetic properties for Me2X samples relatively resemble those of MeFe2O4 spinel ferrites, which suggests that Me2+ cations are distributed in spinel blocks in the Me2X crystal structure.抄録全体を表示PDF形式でダウンロード (829K)
国際研究集会派遣助成事業報告
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関口 達也2010 年 57 巻 12 号 p. 814-815
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (733K) -
Threrujirapapong Thosaphon2010 年 57 巻 12 号 p. 816-817
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (266K)
本会記事
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2010 年 57 巻 12 号 p. Pref12_1
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (375K) -
2010 年 57 巻 12 号 p. Mtg12_2-Mtg12_5
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (259K)
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2010 年 57 巻 12 号 p. Index57_1-Index57_16
発行日: 2010年
公開日: 2011/01/19
ジャーナル オープンアクセスPDF形式でダウンロード (442K)
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