巻号一覧
68 巻, 10 号
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引地 貴義, 小宮山 崇夫, 大貫 仁2004 年 68 巻 10 号 p. 851-856
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーA new surface cleaning process for steel materials using CO gas generated by the decomposition of ethanol has been investigated. Steel wires were heated in vaporized ethanol at 1233 K at reduced pressures of 600 Pa and 2 kPa by varying ethanol concentrations in an aqueous solution. Surface morphologies and oxides of steel wires were examined using SEM, XRD, XPS and AES.
It was confirmed that iron wires were cleaned by the heating in an aqueous solution containing ethanol greater than 0.6% at a pressure of 600 Pa. The cleaning mechanism of iron wires was investigated.抄録全体を表示PDF形式でダウンロード (1063K) -
吉川 昇, 北原 学, 山口 英明, 谷口 尚司2004 年 68 巻 10 号 p. 857-861
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーIt is difficult to purify Al scrap by means of the general refining process, because of iron impurity, so they are diluted with new Al metal and reused. In the author's previous report, attempts were made to utilize the Al scrap for fabrication of the composite materials by displacement reaction between molten scrap and vitreous silica (SiO2).
In this study, influence of impurities (Fe, Cu, Mg, Si, Sn) on the displacement reaction rate was investigated, the elements of which are present in the Al scraps derived from window frames.
It was shown that the reaction rate was not decreased very much by addition of the elements within the composition range of the Al scrap. However, Mg addition to Al decreased the rate more than the other elements. A composite body consisting of Al and Al2O3 phases is formed by displacement reaction between molten pure Al and SiO2, but when molten scrap is reacted with SiO2, Mg was contained in Al2O3 phase, and the other impurities were contained in the metal (Al) phase. Fe and Cu have interaction with Si (by-product of the reaction), resulted in the higher Si content in the metal phase. On the contrary, this tendency was not obvious in Al-Sn reaction case.抄録全体を表示PDF形式でダウンロード (928K) -
森田 辰郎, 三阪 佳孝, 川嵜 一博, 飯塚 高志2004 年 68 巻 10 号 p. 862-867
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーThe effects of short-time 2-stage induction heat treatment on the microstructure and mechanical properties of Ti-6Al-4V alloy were investigated. After the alloy was solution-treated at temperatures in the α+β field (1243 K) and in the β field (1373 K) for 60 s and was water-quenched, it was aged at 773 K for 40 s, 0.6 ks and 1.8 ks. Through the above 2-stage heat treatment, the β-phase was transformed to an α′ martensite phase possessing a high hardness, and then fine a α-phase was precipitated in the α′-phase. With this change in the microstructure, the 0.2% proof stress and tensile strength were remarkably improved while the reduction of area was decreased. The decrease of the ductility was especially significant in the alloy solution-treated at 1373 K above β transus and aged. In all of the examined conditions, the appropriate heat treatment was the treatment consisting of solution treatment at 1243 K for 60 s and aging at 773 K for 40 s. This heat treatment increased the 0.2% proof stress and tensile strength by 33% and 31%, respectively, for a short time and held the reduction of area at 17%.抄録全体を表示PDF形式でダウンロード (1216K) -
喜多 勇人, 木本 雅也, 工藤 赳夫2004 年 68 巻 10 号 p. 868-872
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーInfluence of environmental factors on corrosion behavior of AZ31 magnesium alloy rolled sheet was investigated and compared with zinc coated steel sheet by three corrosion test methods, such as salt immersion test (SIT), salt spray test (SST) and combined corrosion cycle test (CCT). Corrosion rate of AZ31 in SIT was increased with NaCl concentration and decreased with pH rising. Zinc coated steel sheet, however, showed little dependence of NaCl concentration and pH. The corrosion rate of AZ31 in three corrosion test methods decreased in the order of SIT>SST>CCT. On the other hand the zinc coated steel sheet showed the reverse tendency. Electrochemical measurements in chloride solution showed that cathodic reactions of AZ31 and zinc coated steel sheet were reductions of water and dissolved oxygen, respectively. It was also clarified that the corrosion of AZ31 was controlled by anodic reaction, while the corrosion of the zinc coated steel sheet was dominated by diffusion of dissolved oxygen. The reverse tendency of the corrosion rates of AZ31 and zinc coated steel sheet in the three test methods can be explained by the fact that the pH rising in the vicinity of the metal surface is accelerated in the order of SIT, SST and CCT, and the diffusion of dissolved oxygen to the metal surface is increased in the same order.抄録全体を表示PDF形式でダウンロード (886K) -
和田山 智正, 有金 剛, 八田 有尹2004 年 68 巻 10 号 p. 873-879
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーVisible light emission from porous silicon (PS) has been investigated in-situ with photoluminescence (PL), Raman, and transmission IR spectroscopies in an ultra-high vacuum. The PL intensity of as-anodized PS was significantly decreased by the first exposure to thermoelectrons accompanied by the intensity reduction of the IR absorption bands due to hydrogenated Si species (Si-Hx; x=1-3). Upon subsequent exposure to H atoms the lost PL intensity was almost recovered but never exceeded its original intensity. This PL recovery was accompanied by regeneration of the Si-Hx bonds. In contrast, an exceeding recovery was observed for the thermoelectron-treated PS after exposure to H2O or O3. Simultaneous IR measurements revealed that Si-OH or Si-O bonds were formed at the PS surface. These results demonstrate that the PL of the PS is closely related to the oxygen-included surface chemical bonds.抄録全体を表示PDF形式でダウンロード (1116K) -
小栗 和也, 西 義武2004 年 68 巻 10 号 p. 880-882
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーWhen the time to clear vision is used as an indicator of mist resistance, we found that the low energy electron beam irradiation enhanced the mist resistance for sapphire lens surface setting on endoscope top. In order to explain the mist resistance by low energy electron beam irradiation, influences of electron beam irradiation on surface conditions were investigated. The electron beam irradiation increased the surface energy. Based on the results of X-ray photoelectron spectroscopy, the electron beam irradiation enhanced the bonding rates of -C-O- and -C-O-O- and decreased -C-C- bonding rate. Thus, the electron beam irradiation decreased contact angle of sessile water drop and increased surface energy, resulting in generating mist resistance of the treatment.抄録全体を表示PDF形式でダウンロード (498K) -
小林 弦幸, 山田 邦男, 西 義武原稿種別: その他
専門分野: その他
2004 年 68 巻 10 号 p. 883-886
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーSi-Ti-C-O (Tyrano) fibers, with their advantages of light weight and high strength, are increasingly being applied as structural materials in the fields of aerospace engineering and rapid transport engineering. In order to evaluate elasticity, fracture stress and strain of the fibers, precisely, twisting has been a serious problem on standard tensile test. Therefore, stress-strain curves have been obtained by using developed twisting relaxation tensile tester, which can be precisely controlled the strain rate. The twisting relaxation apparently enhances the fracture stress and increases the fracture strain of Si-Ti-C-O (Tyrano) fibers. The effects of twisting relaxation on fracture toughness explained by the strain relaxation of twisted fiber.抄録全体を表示PDF形式でダウンロード (673K) -
田口 正美, 福井 啓吾2004 年 68 巻 10 号 p. 887-893
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーIn order to investigate the early stages of discharge-charge of the active materials for positive electrode in the lead-acid battery, a PbO2 thin film was prepared by reactive sputtering, and then cyclic voltammetry on the PbO2 film electrode was repeated 5 times in various H2SO4 solutions ranging from 0.1 to 2.0 kmol m-3 in concentration at 303 K. The mass change of the PbO2 film electrode was in situ observed using the electrochemical quartz crystal microbalance (EQCM) technique. The mass of the active material of positive electrode, PbO2 increases during the discharge reaction of PbO2→PbSO4 and it decreases during charge reaction of PbSO4→PbO2. A part of the discharge product, PbSO4 was not restored to its original state, PbO2 on 1∼3 cycles of discharge-charge, although the mass change curves had the loop shapes on 4∼5 cycles. The discharge-charge became steady-state and the current efficiency of discharge was nearly equal to that of charge on and after 4 cycle. On the other hand, the average grain size of the discharge product, PbSO4 in 0.1 kmol m-3 H2SO4 solution was about 0.35 μm and it was considerably smaller than those in 0.5∼2.0 kmol m-3 H2SO4 solutions. Moreover, the utilization rate of PbO2 in the former solution is approximately 6∼8% higher than those in the latter solutions. It may be concluded from the results that the utilization rate of PbO2 depends on the shape of the PbSO4 crystal produced by the first discharge. Therefore, it seems that refining the grain size of the first discharge product is of great significance for the improvement of the discharge-charge property of the active materials for positive electrode in the lead-acid battery.抄録全体を表示PDF形式でダウンロード (1435K) -
星 恵理子, 北田 正弘2004 年 68 巻 10 号 p. 894-898
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーThe effects of metallic elements on the degradation of Japanese paper have been investigated. A hand-coloured wooden engraving print from the late Edo era and a Japanese paper decorated with metal foils from the Meiji era are used as naturally aged specimens. Metal tarnishing and paper degradation are observed in both specimens. The metal powder is observed with an optical microscope and SEM. Elements contained in the specimen are measured by means of EDX. Degradation of the paper is examined with a three-dimensional fluorescence spectrometer (TDFS). The metal foils examined with XRD. (1) On the wooden engraving print, the concentration of metal powder is Cu-28 mass%Zn. The results of TDFS and EDX show that the Cu species diffuse from the right to the wrong side of the paper. (2) On the decorated Japanese paper, the metal foil concentration is Cu-16 mass%Zn. Spheroidal grains and plate grains are observed in the tarnished parts of the foil. Cu, Zn, S and Cl are detected in these parts. The compounds Cu2O, CuSO4·2Cu(OH)2 and CuCl are detected by XRD. However, only Cu species diffuses into the cellulose. Therefore, it is thought that the degradation of Japanese paper is due to diffused Cu species.抄録全体を表示PDF形式でダウンロード (924K) -
早川 正夫, 松岡 三郎, 古谷 佳之, 小野 嘉則, 鈴木 功, 鴻巣 喬2004 年 68 巻 10 号 p. 899-903
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーA new observation method was developed for visualizing microstructure on a chemical-mechanically polished (CMP) surface for tempered martensite of a medium-carbon steel (JIS-SCM440).
The CMP and an electropolished (EP) surfaces were observed using an atomic force microscope (AFM) and a field emission type-scanning electron microscope (FE-SEM), respectively. AFM images, FE-secondary and backscattering electron images and electron backscattering patterns (EBSP) were obtained for the CMP and EP surfaces.
The AFM and FE-secondary electron images of the EP surface clearly visualized blocks and cementite particles, since the unevenness corresponding to blocks and cementite particles were formed by the electropolishing.
On the other hand, the AFM image of the CMP surface revealed that the CMP process produced a very smooth surface with unevenness not exceeding 10 nm. The FE-backscattering electron images of the CMP surface only visualized the crystal-misorientation of the martensite matrix microstructure clearly, since the images are not influenced by the surface unevenness.
The CMP surface is more appropriate than the EP surface for the EBSP measurement, since the unevenness of the CMP surface is smoother than that of the EP surface. Blocks with high-angle boundary beyond 15° could be recognized by EBSP mapping, but laths with low-angle boundary bellow 3° could not be done.抄録全体を表示PDF形式でダウンロード (1263K) -
山内 貴志, 高原 良博, 成田 舒孝2004 年 68 巻 10 号 p. 904-907
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーLocal electronic structure around adatom vacancies on Si(111)-7×7 surface has been investigated using STM (scanning tunneling microscopy) and STS (scanning tunneling spectroscopy). The nearest neighbor adatom to a vacancy appears bright in the STM observations, while the brightness of the other neighbor adatoms are almost unchanged. The nearest neighbor adatom slightly approaches to the vacancy, while the other neighbor adatoms do not change their location. These results suggest that the electronic states between the vacancy and its nearest neighbor adatom are changed. In the STS spectra for each type of adatom vacancies, a new state appears at about 0.5 eV below the Fermi level. The new state also appears in the STS spectra for the nearest neighbor adatom of the vacancies. Thus, it is clear that the state about 0.5 eV below Fermi level is associated with the localized vacancy level.抄録全体を表示PDF形式でダウンロード (644K) -
山本 玲緒, 武田 靖子, 横山 浩樹, 木村 隆, 西田 憲二, 前田 繁則, 寺本 元信2004 年 68 巻 10 号 p. 908-912
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーFollowing lead regulation in recent years, the application of lead-free solder is necessary in the field of multilayered thin-film solder on AlN heat-sink for Laser Diode (LD) mounting.
In present study, the melting point of solder and the adhesion strength with LD have been investigated in regarded to the film construction for Sn-10 mass%Au, Ag, and Bi multi-layers. The melting point of multilayered thin-film solder is varied depending on the sequence of the layers. The lowest melting point (453.5 K) was observed, in the case of film construction evaporated Bi layer between Ag layers.
The adhesion strength was decreased, as the surface roughness (Ra and Rmax) of the film surface increased. This observation was explained by change of contact state, the contacting area of solder and LD has decreased when the surface roughness increased. We have found that it is necessary to design the film construction that surface roughness of solder could decrease for good LD mounting.抄録全体を表示PDF形式でダウンロード (988K) -
金 炳男, 平賀 啓二郎, 森田 孝治2004 年 68 巻 10 号 p. 913-918
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーA theoretical relationship is derived between the kinetics of normal grain growth and the size distribution of small grains. When the distribution of the normalized grain size r is proportional to rm around r=0 in a steady state, the grain growth exponent n is revealed to be m+1. The same relationship is also derived from the analysis of the mean field model. The validity of this relationship is confirmed from the consistence with existing grain-growth models and numerical simulations. Experimental consistence is observed with the size distribution on sectional surface. It is found that a log-normal function is not a steady-state size distribution for normal grain growth with n=2, even though it may approximate experimental size distributions. The obtained relationship is also shown to be applicable to particle coarsening by Ostwald-ripening.抄録全体を表示PDF形式でダウンロード (817K) -
宮原 広郁, 奈良 正功, 奥川 誠之, 大城 桂作2004 年 68 巻 10 号 p. 919-926
発行日: 2004年
公開日: 2005/06/24
ジャーナル フリーThe microstructure of polycrystalline silicon has been investigated through a unidirectional solidification technique, and the mechanism of the twin growth on a reentrant corner has been evaluated. A columnar structure is observed in the rod-like silicone specimens, which are solidified at a velocity from 1.25 to 40 μm/s in an electric resistance furnace with a positive temperature gradient of 20 K/cm. At slow velocity from 1.25 to 2.5 μm/s, the grain sizes increase as solidification proceeds. However, mean grain sizes decrease with increasing solidification velocity, and at the central part of specimens the equiaxed grains appear above a critical velocity of around 40 μm/s. Most of the columnar grains have twin boundaries in them, and grains with several twins grow larger than twin-free grains. To increase grain size, it is necessary to keep the solidification velocity low and to introduce the twins. The supercooling of directional growth is less than 4 K at a velocity from 2.5 to 30 μm/s. A model of two-dimensional nucleation on the reentrant corner has been established and their critical nucleation radii are calculated from 70% to 80% of the radii of those of general two-dimensional nucleation. The decrease of the critical radius on the reentrant corner would reduce the supercooling of grain growth. Therefore, the grains with twins could preferentially grow and enlarge in a competitive growth.抄録全体を表示PDF形式でダウンロード (1604K)
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