巻号一覧
59 巻, 9 号
September
選択された号の論文の16件中1～16を表示しています
- |<
- <
- 1
- >
- >|
研究
研究
-
波多野 桂一, 土信田 豊, 水野 洋一2012 年 59 巻 9 号 p. 507-512
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスThe microstructural evolution and piezoelectric properties of Na0.5K0.5NbO3 ceramics by adding K3Nb3O6Si2O7 (NKN+x mol% KNS; x=0.0, 0.3, 0.7, 1.4) were investigated. The advantageous effect of the additive KNS for NKN ceramics was good sinterability for well controlled particle size distribution during sinter process. The rate of sintering shrinkage of NKN was improved from 8 % to over 13 % by adding KNS. The NKN+0.3 mol% KNS ceramics exhibited that the median diameter for a particle size decreased significantly from 2.2 μm (for NKN) to 1.3 μm, and also the maximum diameter decreased from 12.3 μm to 5.3 μm. In addition, the piezoelectric constant, d33, and the electromechanical coupling factor for the radial mode, kr of NKN+0.3 mol% KNS were 130pC/N and 39.6 % respectively. The well controlled microstructure of NKN ceramics by adding KNS possessed higher reliability. The break-down voltage of NKN+0.7 mol% KNS showed over 11 kV·mm-1 in silicone oil at 150°C. The additive KNS for NKN implied to prevent evaporation of K2O during sintering process, which is believed to be derived from the crystal structure of KNS.抄録全体を表示PDF形式でダウンロード (1163K) -
世利 修美, 蓑島 創2012 年 59 巻 9 号 p. 513-516
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスMagnesium titanate powders with a few micron sizes were successfully prepared by mixtures of both corrosion products of titanium in alkaline hydrogen peroxide solution and magnesium in nitric acid solution. MgTiO3 powders sintered at 923∼1523 K for 7.2 ks were characterized by X-ray diffraction and their surface morphology was observed by scanning electron microscopy. The average particle size distribution was detected in the range of 0.3∼10 μm. It is considered that the corrosion synthesis has some advantages compared to other methods in inorganic syntheses.抄録全体を表示PDF形式でダウンロード (566K)
研究速報
-
Takashi Shirai, Koji Orito, Tran Thi Thu Hien, Masayoshi Fuji2012 年 59 巻 9 号 p. 517-521
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスA "non-firing ceramic process" for producing high-strength ceramic solids without calcination is developed. In this process, a ceramic powder, activated by mechanochemical processing, is dispersed in an alkaline solvent to dissolve any metallic ions in the powder and to form precipitates between grains via reprecipitation. The ash powder of the incinerated paper sludge (PS ash, waste generated during paper recycling) is subjected to mechanochemical processing using a planetary ball mill, and non-fired compacts are prepared by wet forming or dry press forming; the effects of different forming methods on the compact properties are investigated. The compacts obtained by the wet forming had a low mechanical strength because the impurities in the PS ash reacted with KOH, resulting in gas emission during solidification and thus in the fracture of already solidified matter through the expansion of gas volume. However, dry press forming yielded good-quality compacts with few defects such as pores and cracks because only the minimum amount of the powders surface necessary for solidification was dissolved and reprecipitated, limiting the excessive dissolution of powder by the KOH solution.抄録全体を表示PDF形式でダウンロード (1384K)
特集：電磁エネルギーを含む非熱的エネルギー支援プロセスによる新機種発現
総報
-
水内 潔2012 年 59 巻 9 号 p. 524-
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスPDF形式でダウンロード (140K)
解説
-
松木 一弘, 冨ヶ原 健翔, 許 哲峰, 崔 龍範, 佐々木 元2012 年 59 巻 9 号 p. 525-531
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスA lot of powders having a low sinterability show the attractive properties for the industrial applications in the point of the energy conservation. The relation between their powders and process parameters in spark sintering was reported for production of sintered compacts with high efficiency and multifunction. The non-equilibrium phase (supersaturated aluminum solid solution), carbides (WC and Cr3C2), oxide (Al2O3), sulfides (MoS2 and WS2), borides (FeB and Fe2B), vapor grow carbon fibers and their composites, were chosen as attractive powders having a low sinterability. The behaviors and process analyses of the spark sintering for their powders were investigated experimentally and theoretically. These compounds were successfully consolidated and showed high densities. Some unique phenomena such as retardation of grain growth, suppression of thermal decomposition and maintenance of initial non-equilibrium phases, were observed by the proper control of process in spark sintering.抄録全体を表示PDF形式でダウンロード (1216K)
研究
-
巻野 勇喜雄, 川原 正和, 阪口 雅, 貝山 由樹, 赤松 勝也, 安野 拓也2012 年 59 巻 9 号 p. 532-537
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスHighly transparent aluminas were synthesized by SPS processing under the conditions of 100 MPa and 200°C/min. High in-line transmittances of about 30 % at λ=400 nm and more than 60 % at λ=800 nm were obtained for the aluminas sintered at 1150°C for 10 min-45 min or at 1200 for 10 min. The in-line transmittance monotonously decreases with the increase of grain size in sintered aluminas and it is indicated that high transparency is attributed to both high densification and submicron grains less than 350 nm, which were realized by high heating rate of 200°C/min and high pressure of 100 MPa. Scarce existence of pores in SPSed aluminas was found by TEM observation and it is also responsible for their high in-line transmittance. Further, it is indicated that higher sintering temperature than 1200°C and longer sintering time, except for 1150°C, degrade the transparency of sintered aluminas.抄録全体を表示PDF形式でダウンロード (1113K) -
巻野 勇喜雄, 川原 正和, 阪口 雅, 貝山 由樹, 赤松 勝也, 安野 拓也2012 年 59 巻 9 号 p. 538-543
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスTransparent aluminas were synthesized by SPS from a commercial alumina powder (AA-02, average grain size; 230 nm, Sumitomo Chemical Co. Ltd., Japan) under the conditions of 100 MPa and 200°C/min in order to examine the influence of raw powder on the transparency. Comparing with the aluminas SPSed using another commercial powder (TMDAR, average grain size; 100 nm, Taimei Chemicals Co. Ltd., Japan), relatively lower transparency was observed for AA-02 SPSed aluminas in the temperature range between 1150°C and 1250°C. On the other hand, a fairly high transparency was obtained for the AA-02 alumina SPSed at 1300°C. The findings are attributed to the larger grain size of AA-02 alumina powder and show the importance of the characters of raw powder for high transparency. In addition, it is suggested that somewhat higher densification temperature in AA-02 alumina leaves fair amount of micropores remained, resulting in the low transparency of AA-02 SPSed aluminas.抄録全体を表示PDF形式でダウンロード (1047K) -
安野 拓也, 川原 正和, 貝山 由樹, 巻野 勇喜雄, 向後 保雄2012 年 59 巻 9 号 p. 544-548
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスAn ultrafine α-alumina powder was consolidated by spark plasma sintering (SPS) and the effect of microstructure on mechanical properties of the sintered compact was examined. The density and bending strength of sintered compact increased with sintering temperature and indicated the maximum value at 1573 K. In the temperature range higher than 1573 K, however, these properties decreased with the increase of sintering temperature. The changes of these properties were clarified by microstructural analysis using transmission electron microscope. It was indicated that the grain growth was fairly encouraged in the consolidation of alumina powder when the powder was consolidated at a sintering temperature higher than 1573 K. On the grain growth process, many fine pores occurred in the grains and/or on the grain boundaries. Further, the bending strength decreased remarkably so that larger pores existed on the grain boundaries at 1773 K.抄録全体を表示PDF形式でダウンロード (1041K) -
高山 定次, 福島 潤, 佐野 三郎, 佐藤 元泰2012 年 59 巻 9 号 p. 549-552
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスThe wavelength is much larger than the dimensions of heated objects in GHz range. It suggests that vectors of magnetic or electric field are equal all over in atomic, molecules and crystal in the materials. As the photon energy is very low, the energy carried by each cycle of the wave is only a few Gauss in the wave propagating with 100 watts/cm3 at 2.45 GHz. The two characters of field uniformity and low energy in the wave vectors suggest that small collective electron motions generate coupled with the wave. If the ordered motions were scattered by some mechanism, the collective (kinetic) motions of electrons would dissipate and accumulate into the materials. On the other, the sintering materials become un-uniformity like uneven crystal orientation and/or heterogeneous as multicomponent. Therefore, each powder in sintering materials has different sensitivity for the collective motions of microwave. For inspecting the interaction between collective motion and un-uniform materials, the Fe3O4 were heated by magnetic field of microwave and by conventional heating. As results, sintered sample heated by magnetic field was observed the local abnormal grain growth.抄録全体を表示PDF形式でダウンロード (1414K) -
Jun Fukushima, Sadatsugu Takayama, Sabro Sano, Motoyasu Sato, Yamato H ...2012 年 59 巻 9 号 p. 553-556
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスThe effect of an H-field or E-field on the sintering and decrystallization of titanium oxides during 2.45 GHz microwave heating was investigated. Titanium oxides (TiO2-x) were heated in a TE103 single-mode cavity, which was used to separate the maximum point of the H-field or E-field of the 2.45 GHz microwave radiation. Scanning electron microscopy (SEM) images taken after H-field heating showed that the sample was sintered well above 1400°C. In the X-ray diffraction (XRD) patterns, the intensity of the diffraction peaks of TiO2 decreased with increasing heating temperature between 1200°C and 1400°C. After heating at 1500°C, however, the TiO2 peak intensities increased and undefined peaks emerged. Decrystallization is the dominant reaction, driven by the nonthermal microwave effect, below 1400°C. As the effect of the thermal energy becomes larger than the nonthermal microwave effect above 1500°C, grain growth becomes the dominant reaction. During E-field heating, the surface structure changes to fiber-like and dot-like structures, while some areas are oxidized by plasma excited by the microwaves.抄録全体を表示PDF形式でダウンロード (1173K)
研究速報
-
水内 潔, 井上 漢龍, 上利 泰幸, 長岡 亨, 杉岡 正美, 田中 基博, 武内 孝, 谷 淳一, 川原 正和, 巻野 勇喜雄, 井藤 ...2012 年 59 巻 9 号 p. 557-563
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスβ-SiC-particle-dispersed-aluminum (Al) matrix composite was fabricated in the solid-liquid co-existent state by the Spark Plasma Sintering (SPS) process from the mixture of β-SiC powders, Al powders and Al-5 mass% Si powders. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were all well consolidated by heating at a temperature range between 798 K and 876 K for 1.56 ks during the SPS process. No reaction at the interface between the β-SiC particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the Al/β-SiC composite fabricated was higher than 99 % in a volume fraction range of SiC between 40 % and 50 %. Thermal conductivity of the Al/β-SiC composite was higher than 200 W/mK in a β-SiC volume fraction range between 40 and 50 vol%. The highest thermal conductivity was obtained for Al-45 vol% β-SiC composite and reached 216 W/mK. The coefficient of thermal expansion of the composites falls in the upper line of Kerner's model, indicating strong bonding between the β-SiC particle and the Al matrix in the composite.抄録全体を表示PDF形式でダウンロード (1447K)
研究
-
高木 健太, 尾崎 公洋2012 年 59 巻 9 号 p. 564-569
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスAnisotropic Zn/Sm2Fe17N3 sintered magnets were successfully fabricated by a high-pressure current sintering as a low-thermal-load sintering technique. Zn/Sm2Fe17N3 powder mixtures, prepared by ball milling and annealing at 450°C, exhibited the high coercivity (Hcj) equivalent to the raw magnet powder. The bulk magnets sintered from the annealed mixtures maintained the high Hcj. Subsequently, unannealed mixtures were directly sintered to perform the annealing and sintering concurrently. This concurrent treatment increased in the sintered density, resulting in improvement of the remanence (Br). For further improvement of Br the Zn additive amount must be reduced, and TEM-EDX analysis for the annealed mixtures implied that the decreases in oxygen contamination enable to reduce the Zn amount.抄録全体を表示PDF形式でダウンロード (969K) -
菊池 源基, 出井 裕, 高橋 雄也2012 年 59 巻 9 号 p. 570-576
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスIn this study, we focused on the sintering performance of SP-700 (Ti-4.5Al-3V-2Mo-2Fe) and mechanical properties of SP-700 reinforced with titanium boride (TiB/SP-700) fabricated by spark plasma sintering (SPS). TiB whiskers formed in titanium by a solid-state reaction of titanium and TiB2 particles were analyzed with scanning electron microscopy and X-ray diffraction. The TiB/SP-700 was sintered at temperatures of 1073, 1173, and 1273 K and a pressure of 70 MPa for 10, 30, and 50 min. The volume fraction of TiB ranged from 1.7 vol% to 19.9 vol%. Tensile tests of TiB/SP-700 were conducted at room temperature, and the effect of TiB volume fraction on the tensile properties of TiB/SP-700 was investigated. The TiB/SP-700 (5.0 vol%) sintered under all conditions had a relative density of over 99.0 vol%. The TiB was perfectly formed from TiB2 particles in SP-700 by SPS under all sintering conditions. In addition, the TiB/SP-700 sintered at 1173 K for 10 min had the maximum tensile strength of 1193 MPa. At all sintering durations, the tensile strengths of TiB/SP-700 decreased at 1273 K.抄録全体を表示PDF形式でダウンロード (1700K)
本会記事
-
2012 年 59 巻 9 号 p. Pref9_1-
発行日: 2012/09/15
公開日: 2012/12/24
ジャーナル オープンアクセスPDF形式でダウンロード (220K) -
2012 年 59 巻 9 号 p. Mtg9_2-Mtg9_6
発行日: 2012年
公開日: 2012/12/24
ジャーナル オープンアクセスPDF形式でダウンロード (250K) -
2012 年 59 巻 9 号 p. MtgPr9_8-MtgPr9_31
発行日: 2012年
公開日: 2012/12/24
ジャーナル オープンアクセスPDF形式でダウンロード (1280K)
- |<
- <
- 1
- >
- >|