Transactions of the Materials Research Society of Japan
Online ISSN : 2188-1650
Print ISSN : 1382-3469
ISSN-L : 1382-3469
最新号
選択された号の論文の5件中1~5を表示しています
Regular Papers
  • M. Sano, T. Takahashi, H. Iizuka, M. Shishido
    2020 年 45 巻 1 号 p. 1-4
    発行日: 2020/02/01
    公開日: 2020/02/01
    ジャーナル 認証あり

      The authors have investigated a new utilization of rice hull, which is one of the agricultural wastes in Japan. This utilization is significant from the viewpoint of recycling. The Rice hull silica carbon (RHSC) materials are manufactured through the procedure of mixing the rice hull particles with a phenol resin, pressure forming, drying, and then carbonizing in nitrogen gas atmosphere at high temperatures. Since rice hulls have the natural porous structure, the RHSC is manufactured as a porous carbon material. Previous research has revealed that this material showed certain properties of excellent friction and wear under the conditions of non-lubrication and seawater atmosphere. Then, this material is applied to slide members such as linear motion guide elements and sliding bearings. The basic properties in RHSC such as compressive strength and bending strength and friction and wear at normal temperature have been clarified. However, the effect of friction and wear at high temperature has not been clarified. In addition, when the material reaches a high temperature, the material tends to crack and oxidize on its surface. Therefore, in order to achieve the practical use of this material at high temperature, it is essential to evaluate the properties of friction and wear at high temperature. In this study, In order to grasp the effect of the temperature of the wear surface on the friction and wear properties of the RHSC, conducted to evaluate friction and wear properties at high temperature.

  • Toshiaki Manaka, Mitsuharu Todai, Takanori Hino
    2020 年 45 巻 1 号 p. 5-7
    発行日: 2020/02/01
    公開日: 2020/02/01
    ジャーナル 認証あり

    In the present paper, behavior of hydrogen in a low carbon high strength steel produced by thermo-mechanical controlling process (TMCP) was investigated by means of tensile testing and silver decoration technique, which can easier visible hydrogen using Ag particles. Tensile tests were performed on the specimens with and without hydrogen charging at a strain rate of 5.6×10-6 s-1. As a result, the hydrogen-charging decreased elongation to failure. It was also clarified that this decreasing of ductility is closely related to the quasi-cleavage fracture by SEM observation of fracture surface on detail. However, the sensitivity of hydrogen embrittlement was lower than that of the as-quenched martensitic steel. After silver decoration treatment, Ag particles distributed homogeneously on the specimen surface, which indicated hydrogen evolved homogeneously from the steel. This implies that it is very complex the mechanism of the hydrogen embrittlement in this high strength steel produced by TMCP due to the fine martensitic microstructure and existence of cementites.

  • Sota Oshima, Siaw Onwona-Agyeman, Norihide Saho, Kwame Sarpong Appiah, ...
    2020 年 45 巻 1 号 p. 9-13
    発行日: 2020/02/01
    公開日: 2020/02/01
    ジャーナル 認証あり

    A new, environmentally friendly, and relatively cheaper fabrication process for mulching boards from sugarcane bagasse is described in this paper. The physical properties of the mulching boards indicate that a mass density of at least 0.4 g/cm3 was necessary for the durability of the mulching boards. In general, the finer boards were more dimensionally stable than the coarser ones. Addition of pearlite, which is a material for improving soil conditions, further enhanced the water absorption capacities of the mulching boards. However, increasing the composition of pearlite also reduced the strengths of the mulching boards. Further tests also revealed that the bagasse-only mulching boards as well as the pearlite-bagasse composite mulching boards did not possess any inhibitory effect on the germination of lettuce. On the whole, all the evaluations suggest that this new material has the potential to replace plastics as mulches in conservation agriculture as well as degraded land restoration projects.

  • Noritaka Kimura, Hiromasa Nasu, Yoshiumi Kohno, Yasumasa Tomita
    2020 年 45 巻 1 号 p. 15-18
    発行日: 2020/02/01
    公開日: 2020/02/01
    ジャーナル 認証あり

    2LiF-NiF2 composites are synthesized by the mechanical milling of LiF and NiF2 in a molar ratio of 2 : 1 for 72 h, and Li2NiF4 are synthesized by calcination at 673 K. The synthesized samples are investigated by XRD, cyclic voltammetry, and charge-discharge measurements. XRD peaks of the 2LiF-NiF2 composite are broad and the discharge capacity is 44 mAh/g at 0.05 C for voltages of 2.0–4.8 V. After calcination, the XRD peaks become sharp and most peaks are agreement with Li2NiF4. Li2NiF4 obtained by calcination shows a discharge capacity of 96 mAh/g at 0.05 C and 118 mAh/g at 0.02 C for voltages of 2.0–4.8 V. 2LiF-NiO composites are also obtained by the milling of LiF and NiO in a molar ratio of 2 : 1 for 72 h, and shows a discharge capacity of 146 mAh/g. The discharge capacity of 2LiF-NiO at 3C was maintained that of 70 % of 0.1C.

  • Jun Kawakami, Chika Osanai, Shunji Ito
    2020 年 45 巻 1 号 p. 19-22
    発行日: 2020/02/01
    公開日: 2020/02/01
    ジャーナル 認証あり

    2-Hydroxytryptanthrin analog (2-(2-hydroxy-12-oxoindolo[2,1-b]quinazolin-6(12H)-ylidene)malononitrile, DCM-T2OH) was synthesized as a near-infrared (NIR) dye for fluorescent imaging. In high-polarity aprotic solvents (acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide), protic solvents (methanol and ethanol), and an aqueous solution containing 20% acetonitrile, both the absorption and fluorescence bands of DCM-T2OH were observed at the NIR region (650–900 nm), which is referred to as the “optical window” of cells and tissues.

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