材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
60 巻 , 6 号
選択された号の論文の15件中1~15を表示しています
特集 セラミック材料
資料
  • 角野 広平, 藤原 力也, 市川 学, 若杉 隆
    2011 年 60 巻 6 号 p. 495-499
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Halide-incorporated chalcogenide glasses, i.e., chalcohalide glasses, have received much attention as the third family of non-oxide glass systems for improving properties of chalcogenide glasses. In this technical note, we report a systematic research on the glass formation and properties of glasses based on GeS2-Sb2S3-CsX (X = Cl, Br, I) systems in which cesium halides are substituted for SbS3/2 of 60GeS2·40SbS3/2 glass. Glasses were obtained until 20mol% substitution of CsCl and CsBr, and 25mol% substitution of CsI for SbS3/2. By the substitution, glass transition temperatures lowered from 315°C by 60 K for CsCl, and by 40 K for CsBr and CsI. Densities decreased, and refractive indices at 980 nm decreased from 2.341 by about 0.2 for 20mol% substitution. Absorption edges at short wavelength side blue-shifted while those of the long wavelength side did not change. Raman spectra were also measured for structural analysis.
論文
  • 伊坂 雄太, 塩見 治久, 稲岡 康二
    2011 年 60 巻 6 号 p. 500-503
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    In this study, tape casting of barium titanate was performed by using water-based slurry. The effects of the amount of dispersant and binder on the behavior of Ba2+ leaching and sheet properties such as linear shrinkage and warpage for sintered sheets were investigated. The amount of Ba2+ leaching was measured by inductively coupled plasma (ICP) emission spectrometry and fluorescent X-ray analysis. After firing at 1250°C and 1300°C for 2h, a linear shrinkage and warpage were measured. It was shown that addition of dispersant leads to an increase in Ba2+ leaching due to a decrease of pH of slurry. Linear shrinkage and warpage of the fired sheets increased at high binder content. The change in the warpage with dispersant was remarkable at high binder content. The warpage can be attributed to the particle packing of the sheet. SEM photographs showed that there is a difference in particle packing between upper and bottom sides of the sheets at high binder content. This leads to differential shrinkage during firing, resulting in greater warpage.
  • 草薙 宏信, 塩野 剛司, 岡本 泰則
    2011 年 60 巻 6 号 p. 504-509
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    In order to synthesize t-ZrO2 containing TiO2 as a stabilizing agent, two kinds of ZrO2 precursors were prepared by coprecipitation method. One was TiO2-ZrO2 system with the compositions of 5∼20mol% of TiO2 and the other was CeO2-TiO2-ZrO2 system with the compositions of total 20mol% of TiO2 and CeO2. Synthesized precursors were calcined at 800°C and then sintered at 1450°C for 3h. In the binary system, t-ZrO2 phase was observed in calcined powders at any content of TiO2. Formation of t-ZrO2 increased with increasing addition of TiO2, and the calcined powder with 18mol% TiO2 was composed of only tetragonal phase at room temperature. For the sintered bodies of the calcined powders, however, t-ZrO2 phase could not be retained, regardless of TiO2 content. For 5∼10mol% TiO2, they are composed of only m-ZrO2 phase, and for 15∼20mol% TiO2, m-ZrO2/ZrTiO4 composites were obtained. Tetragonal zirconia polycrystal (TZP) could not be obtained. In the ternary system, t-ZrO2 phase was also obtained by calcination of precursors at any content of TiO2 and CeO2. The sintered body consisted of only t-ZrO2 phase by using the powder with 10mol% TiO2 and 10mol% CeO2. The polycrystal has the relative density of approximately 98%.
  • 竹内 信行, 林 辰哉, 小林 久芳
    2011 年 60 巻 6 号 p. 510-514
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Room temperature (R.T.) resistivity and the positive temperature coefficient of resistivity (PTCR) of Gd-Mn codoped BaTiO3 from powders obtained by hydrothermal synthesis were investigated. Mixtures of Gd(NO3)3, Mn(NO3)2, and BaTiO3 powders (average particle size ; 0.5μm) obtained by hydrothermal synthesis were dried and pressed into pellets with a diameter of 2 cm. Then, the pellets fired at 1380°C for 2 h in 0.1%H2-Ar atmosphere and oxidized at the temperature range of 1000 to 1300°C for 1h during cooling period. Fired sample which had low R.T. resistivity and remarkable PTCR characteristics was obtained for 0.2 mol%Gd-0.075mol%Mn codoped BaTiO3 which fired at 1380°C in 0.1%H2-Ar, oxidized for 1h at 1300°C and cooled to R. T. in air. PTCR jump of the sample cooled in air was 300times higher than that of the sample cooled in 0.1%H2-Ar. This result indicated that absorbed oxygen which was introduced into grain boundary by oxidation at 1300°C, was not desorbed during cooling in air from 1300 to 1200°C.
  • 落合 ひとみ, 塩見 治久, 福井 良太, 山本 莉沙子
    2011 年 60 巻 6 号 p. 515-520
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Hydrotalcite like material is an inorganic one having a layered double hydroxide structure (LDH) and one of promising materials for the use of various anion exchangers.In this study, the effects of milling and calcination conditions were investigated on the removal efficiencies of phosphorous of the CO32--hydrotalcite.Commercial CO32--hydrotalcite was milled with a vibrating ball mill under dry condition and followed by calcinations at various temperatures from 200 to 800°C. For un-ground hydrotalcite, calcination at 500°C led to the highest removal efficiencies of phosphorous. On the other hand, the hydrotalcite dry-milled with a vibrating ball mill for 24h showed the highest removal efficiencies of phosphorous on calcining at 200°C. The phosphorous removal by the hydrotalcite calcined at 500°C probably proceeds due to the rehydration of oxide phase, which is precipitated during calcination, accompanied with the re-structure of LDH and intercalation of phosphoric ions. For the hydrotalcite dry-milled and calcined at 200°C, the LDH structure still remains but almost all interlayer water is eliminated during milling and calcining. Therefore, phosphoric ion seems to be easily intercalated into interlayer space between host hydroxide layers. From these results, it is suggested that dry-milling with a vibrating ball mill is effective to reduce calcination temperature for the improvement in the removal ability of phosphorous of CO32--hydrotalcite.
論文
  • 尾崎 拓也, 高木 知弘, 佐藤 広嗣
    2011 年 60 巻 6 号 p. 521-526
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Filled PTFE gaskets have been developed to improve a viscosity performance of PTFE which leads to a leak of inner fluid. However, the performance evaluation methods of the gasket in an actual bolted flanged connection are not reported so far. In this study, the mechanical behaviors of the pipe flange connection with the filled PTFE gasket are investigated by the finite element method considering the visco-elastic-plastic properties of the gasket. First, the visco-elastic-plastic properties of the gasket, or stress-strain and creep curves, are obtained by compression tests and those data are identified to used in the finite element simulations. Next, the bolt load relaxation and the gasket contact stress in the pipe flange connection are estimated by the finite element simulations. Finally, it is concluded that the filled PTFE gasket has much more excellent performance comparing to the pure PTFE gasket in the real pipe flange connection. Furthermore, the important design factors in the gasket development are clarified through systematic simulations.
  • 村瀬 勝彦, 西村 尚哉, 恩田 貴量
    2011 年 60 巻 6 号 p. 527-532
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Many thin wall closed section members made of steel are used for the traffic machine such as an automobile. In these members, the local buckling under compressive stress is mentioned as a main problem. As a method for improving the performance, the technique which fills the inside of closed section with the low-density foaming material is used. In this study, axial compression and 3-point bending tests were carried out on the composite material which filled 2 kinds of epoxy resin foaming material in which the foaming rate (density) is different for hat type thin-walled cross section member. The difference of composite member and thin-walled member was investigated on elasticity and plastic collapse characteristics at the various deformation velocities. The adhesive strength between thin-walled member and foaming material, and filling effect of the foaming material in the energy absorption characteristics was clarified.
  • 吉川 高正, 山下 祐輝, 稲葉 忠司, 徳田 正孝
    2011 年 60 巻 6 号 p. 533-539
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    Bulk metallic glass (BMG) is a kind of alloy with amorphous structure and it has better thermal stability because of its atomic composition. In particular, zirconium-based BMGs are expected to apply for structural materials, because they exhibit excellent mechanical properties, a high corrosion resistance, etc. BMGs exhibit a brittle fracture behavior caused by the rapid propagation of a shear band under tensile load at room temperature (RT). On the other hand, BMGs show the high formability due to very large plastic deformation under high temperature condition. And sometimes BMGs are crystallized by thermoplastic deformation even though its thermal condition is never beyond the time-temperature-transformation (TTT) curve of the material. When crystalline particles make the propagation of the shear band stop and deflect, such an effect can bring about an apparent inelastic strain under the tensile load at RT.
    In this study, the development of the ductile property with the inelastic strain of Zr55Cu30Al10Ni5 BMG at RT was attempted by applying crystallization with thermoplastic deformation. The experimental results suggested that the thermoplastic deformation with strain rate of 2.0 × 10-4s-1 or 3.0 × 10-3s-1 can bring about the inelastic strain to Zr55Cu30Al10Ni5 BMG at RT under tensile loading by precipitating the crystalline particles in the material.
  • 宮崎 信弥, 馬場 秀成
    2011 年 60 巻 6 号 p. 540-546
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    High cycle fatigue tests and computational studies of a coarse-grained Ni alloy were carried out to investigate fatigue crack nucleation and propagation behavior. Fatigue tests of a rectangular sample were performed by four-point bending under load control. Several interruptions were made to observe fatigue crack nucleation and propagations in the gauge region. Grain distribution and orientation of the tensile surface were characterized using electron beam backscattering diffraction pattern (EBSP) technique. A size of characterizing area was determined to sufficiently cover the inner span of four-point bending. Polycrystalline finite element analysis was made to investigate stress distributions of the specimen. Stresses were computed in global axis, such as longitudinal stress, and local axis, such as resolved shear stresses in slip systems, for whole grains. Longitudinal stress distributions tend to be affected by inter-grain relationships. Fatigue crack initiations tend to be occurred in areas indicating relatively high resolved shear stresses in slip systems.
  • 菊池 将一, 廣田 遥, 小茂鳥 潤
    2011 年 60 巻 6 号 p. 547-553
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    In order to determine the fine particle peening (FPP) treatment conditions that generate a high compressive residual stress, the effect of specimen hardness and shot particle hardness on residual stress was investigated. The results showed that the higher the generated specimen hardness, the higher the compressive residual stress at the surface. Additionally, in the case of high hardness specimens, the shot particle hardness affected the residual stress. This was because shot particle was deformed during the FPP treatment process. Furthermore, in order to clarify the effect of FPP treatment on fatigue properties of SCM435H steel with different hardnesses, fatigue tests were performed at room temperature using a rotational bending fatigue testing machine. In the case of higher hardness substrate, the fatigue strength was dominantly increased by FPP treatment ; however, in the case of lower hardness substrate, the increasing level was very small. This was because compressive residual stress generated on the surface of higher hardness specimen was much larger than that generated on lower hardness specimen and the higher compressive residual stress remained on the surface of higher hardness specimen under the application of cyclic loading. These results indicate that the FPP treatment is highly significant to improve the fatigue strength for higher hardness substrate.
再録論文
  • English version of the paper published in “Journal of the Society of Materials Science, Japan, 57 (11) : 1167-1172 (2008)”
    Zhiren WU, Kentaro IWASHITA, Zhishen WU, Hirondo INAGAKI
    2011 年 60 巻 6 号 p. 554-559
    発行日: 2011/06/15
    公開日: 2011/06/21
    ジャーナル フリー
    The slurry scattering technique has been widely accepted as a method for fixing moving sand. Using an organic slurry that has high water retention capacity may allow for the growth of vegetation in the desert. However, organic material in the slurry, such as hydrophilic polyurethane, is easily decomposed by ultraviolet irradiation, and ultraviolet rays are extremely strong in the desert. The goal of this paper is to examine, in terms of strength and decomposition rate, the ultraviolet resistance of sand stabilized with an organic slurry containing hydrophilic polyurethane. Adding emulsified asphalt improved the ultraviolet resistance of the stabilized sand. Although all of the asphalt emulsions used in the experiment have similar beneficial effects, the nonionic emulsified asphalt is considered to be one of the best solutions due to its neutrality. Moreover, the ultraviolet resistance of the stabilized sand can be controlled by changing the mixing ratio of the emulsified asphalt. By mixing the emulsified asphalt in the slurry at ratios of 5%, 6∼8%, and 9%, the weight loss rate due to ultraviolet irradiation was 1.5∼1.8 times, 2.1∼5.4 times, and 4.7∼18.2 times smaller respectively.
講座
国内外トピックス
部門・研究委員会活動
feedback
Top