著者

辛島 恵美子

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.66, no.12, pp.1236-1245, 2002 (Released:2008-04-24)

参考文献数

27

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The Shinkansen Line has experienced no serious car-accidents since its operation start in 1964. Why has the Shinkansen Line been able to keep such a good safety performance? This paper intends to clarify the background and the reasons why those miracles became possible—when, what kinds of risks and what kinds of actions the staff of the Japanese National Railways took in, who participated in the development of the Tokaido Shinkansen railway-axles in 1950s∼1960s as a designer, an investigator, a maintenance engineer, an inspector, or a top executive in technology. I discovered all the staff had been dedicated to their duties and their actions were prudent enough in general. As a result their behaviors have reduced the riskiness of their works objectively. But the most of the staff were not so much sensitive to risk itself as a few technical top executives of JNR. For example when the inspectors first found unexpected micro cracks on the 20% running axles in 1965, the top executives adapted a new management system in 1966 based on those inspections, which contained a systematic long-range R&D plan of high-quality railway-axles as well as an effective risk management for micro cracks.

著者

梅川 莊吉

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.18, no.8, pp.449-452, 1954 (Released:2008-04-04)

参考文献数

6

被引用文献数

2

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Young’s modulus and its change accompanied by heat-treatment and by cold-working in gold-silver and gold-copper alloys has been measured by lateral vibration method of a cantilever under small amount of stress. The composition dependence of Young’s modulus is monotonous in both alloy systems. Young’s modulus of Cu3Au increases and of CuAu decreases the superlattice formation. The effect of cold work on Young’s modulus is similar for some gold-silver alloys, but it differs considerably with some gold-copper alloys.

著者

釘屋 奈都子 永田 和宏 北田 正弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.78, no.4, pp.149-158, 2014 (Released:2014-04-01)

参考文献数

14

被引用文献数

1 4

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The manufacturing technique of steel chains used for four Japanese armatures from the end of Muromachi to the Edo period has been investigated. The chains used in Kusazuri (tasset) and two types of Kote (guntlet) were composed of steel rings in round and oval shapes while those used in Kusarikatabira (chainmail) was only round. As for the former ones, round rings were connected by oval rings. The diameter of steel wire of rings was about 1 mm. The steel wire was produced from steel plate with the carbon content of 0.11 to 0.40 mass%. Steel was forge-and-welded twice to make in plate and was cut in a bar. The steel bar was drawn into standardized wires by die with the draft percentage of about 25% and annealed. Drawing of standardized wire followed by annealing was repeated several times to make a wire for armatures. The crystal grains in wires were elongated in axial direction and the aspect ratio of grain in oval rings was larger than that in round rings. A wire was rolled around a stick and cut by chisel to make rings.

著者

杉岡 奈穂子 北田 正弘 西嶋 雅彦

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.77, no.5, pp.185-191, 2013 (Released:2013-05-01)

参考文献数

15

被引用文献数

2

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The metallurgical microstructure and mechanical properties of the spear blade manufactured in the Edo period have been investigated. The purpose of this work is to obtain metallographic data of the spear blade, and to clarify the manufacturing technique of the spear blade. The specimen examined was estimated to have been made from the end of the Muromachi period to the Edo period and has the signature of Shinano-no-Kami Minamoto Takamichi. The spear is 31 cm in length and 10.7 mm in maximum width. The metallurgical microstructure and nonmetallic inclusions of the spear blade are observed using an optical microscope. The carbon concentration is determined by chemical analysis. To evaluate the hardness, micro Vickers hardness (Hmv) is used. The microstructure is observed using an optical microscope and a scanning electron microscope (SEM). The concentration of nonmetallic inclusions is obtained by electron dispersive X-ray analysis (EDS).    A cross-sectional image of the spear after chemical etching shows a metal flow pattern formed by deformation, possibly created by hammering. The striped structure of layers of two types of steel containing different carbon contents stacked on top of each other was observed. The bright areas after etching corresponded to the edges and ridges of the spear, which were cooled rapidly, forming the martensite structure. The other dark areas consist of pearlite and α-Fe (ferrite) grains. Optical micrographs of near-edge areas contain pearlite and martensite grains, and core areas contain pearlite and α-Fe grains. The nonmetallic inclusions in the core steel consist of a few metal oxide particles and a glass matrix. There are Fe-Ti oxide grains in the glass matrix, and an unknown oxide particle adhering on the Fe-Ti oxide grain surface was also observed.

著者

翠川 裕 仲井 正昭 翠川 薫 新家 光雄

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.80, no.3, pp.165-170, 2016 (Released:2016-02-25)

参考文献数

10

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A novel method for detecting antimicrobial activity using an innate property of the Salmonella bacteria, namely, the ability of Salmonella to produce hydrogen sulfide (H2S) was developed in this study. The effectiveness of the method was evaluated by comparing the antibacterial activity of copper to that of aluminum. Salmonella was inoculated over the entire surface of deoxycholate hydrogen sulfide lactose (DHL) agar plates that included Ammonium ferric citrate (C6H8FeN). Approximately 25 μL of cupric chloride (CuCl2, 1% weight ratio) solution or aluminum chloride (AlCl3, 1% weight ratio) solution was added to the center of the medium. The surface of the medium was covered with plastic PET (polyethylene terephthalate) material to induce an anaerobic state. Salmonella was cultured under anaerobic conditions at 310 K (37℃) for 86.4 ks (24 h). The antibacterial activity of copper was determined by observing the medium surface color change due to iron sulfide (FeS) formation, which was caused by the production of H2S by Salmonella; blackness indicated presence of newly formed FeS. A quantitative evaluation of copper's antimicrobial activity was performed using a gradient of CuCl2 concentrations; results were compared with those of the present standard method, Kirby-Bauer disk diffusion method on the Mueller Hinton medium. Finally, in order to evaluate the antibacterial activity of metals, Salmonella was inoculated on DHL agar plates. Subsequently, Japanese coins (1 yen, 5 yen, 10 yen, 50 yen, 100 yen and 500 yen coins) were placed on the agar and cultured at 310 K for 86 ks. Salmonella cultured in the presence of AlCl3 produces black color, while no blackening is observed with CuCl2, suggesting that copper possesses an antibacterial property against Salmonella. CuCl2 suppresses H2S production by Salmonella, as Cu2+ forms a transparent circle or ellipse (new halo) around the point at which CuCl2 had has been plated. The size of the new halo increases in direct proportion to the concentration of CuCl2. The halo is no longer visible at 0.034 mg of CuCl2 in our method, while the halo disappears with 4.34 mg of CuCl2 in the Kirby-Bauer method. Therefore, the present method is 129 times more sensitive than the standard method, suggesting increased usefulness and effectiveness in testing antibacterial activity. No FeS-dependent black circle is formed under any of the coins, with the exception of the 1-yen coin, which contains aluminum and no copper. Therefore, the copper-containing coins have an antibacterial effect.

著者

小川 渉 菖蒲 敬久 筧 瑞恵 鞍谷 文保 小出 俊雄 文珠 義之 水田 泰次

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.83, no.4, pp.128-135, 2019-04-01 (Released:2019-03-25)

参考文献数

9

被引用文献数

3 3

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Cymbals are percussion musical instruments with a simpler structure than other musical instruments. Therefore, their material composition basically decides the sound quality and decay time rather than the skill of the player. In this study, specimens of cymbals to which Titanium, Zirconium and Iron were added were prepared. From the difference of diffraction rings by synchrotron radiation X-rays, the crystal structure of the specimens of cymbals prepared by various manufacturing processes was analyzed in order to investigate the relationship between the crystal structure associated with the material and manufacturing process used and the damping of the sound of cymbals. As a result, it was found that the changes in the crystal structure were due to the manufacturing process used. In addition, it was clarified that the changes affected the damping of the sound of cymbals.

著者

原田 幸明 島田 正典 井島 清

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.71, no.10, pp.831-839, 2007 (Released:2007-10-01)

参考文献数

8

被引用文献数

11 12

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Forecasting are made regarding the consumption up to 2050 of following metals: Fe, Al, Cu, Mn, Zn, Cr, Pb, Ni, Si, Sn, rare earths, Mo, Li, Sb, W, Ag, Co, In, Au, Ga, Pt and Pd. The forecasts are based on the liniar decoupling model of the relation between per capita metal consumption and per capita GDP. The models of each metal are applied to the economic development model of BRICs and G6 countries. According these forecasts, the overall consumption of metals in 2050 will be five times greater than the current levels, and demand for metals, such as Au, Ag, Cu, Ni, Sn, Zn, Pb, and Sb, is expected to be several times greater than the amount of their respective reserves. Demand for iron and platinum, which is considered to be optimistic about the resource exhaustion, will also exceed the current reserves. Urgent measures are needed to find alternatives from common resources and to shift into materials circulation society.

著者

藤田 浩示 高原 良博

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.71, no.12, pp.1071-1074, 2007 (Released:2007-12-01)

参考文献数

6

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Recently, research and development using ultraviolet rays is being conducted in the bioscience field. In such R&D, expensive quartz glass is most often used as the ultraviolet transmitting material. The authors have been studying the use of inexpensive soda-lime glass as an alternative to quartz. In this study the authors investigated the effects of iron oxide and titanium oxide, which are found in raw materials, and crucible materials on the ultraviolet transmission properties of soda-lime glass. It was found that by reducing the amount of Fe2O3 and TiO2 contained in raw materials as impurities, it was possible for soda-lime glass to achieve high ultraviolet transmissivity. Reducing the amount of iron oxide turned out to be an especially effective way to improve ultraviolet transmissivity.

著者

八木 良平 岡部 徹

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.80, no.6, pp.341-349, 2016 (Released:2016-05-25)

参考文献数

59

被引用文献数

3 13

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Rhenium (Re) is used as additives in several alloys such as nickel-based superalloys for jet engine turbine blades, platinum catalysts for oil refining, and thermocouples used at ultra-high temperature, in order to improve strength and stability at high temperature. The demand of Re has been increasing with the increase in demand of the superalloys. In this article, current status such as demand and distribution of Re are reviewed, and smelting technologies for recovering Re from various ores are introduced.

著者

桐野 文良 大野 直志 田口 智子 根津 暁充 横山 亮一

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

2019

---

<p>The production processes of old Japanese coins, <i>Genbun-koban</i>, <i>Akita-ginban</i> and <i>Morioka-ginban</i>, were studied. These coins were manufactured by a forging method in the <i>Edo</i>-era. <i>Genbun-koban</i>, manufactured at a gold mint of the <i>Tokugawa</i> shogunate called <i>Kinza</i>, in 1736, is made of Au-Ag alloy and its surface is not flat. The residual stress of this coin is compressive, and the residual stress in the stamped area is higher than that in the flat area. The <i>Iroage</i> method was used to color the coin; it is a thermal treatment, resulting in lows the residual stress is smaller at flat area. <i>Akita-ginban</i>, manufactured in the <i>Akita</i> domain in 1863 is made of pure Ag and its surface is also not flat. There is no residual stress in this coin. This result shows that the thermal treatment of this coin was carried out after processing. <i>Morioka-ginban</i>, manufactured in the <i>Morioka</i> domain in 1868, is made of pure Ag, and its surface is flat. The residual stress of this coin is compressive, and the residual stress in the stamped area is higher than that in the flat area. This result shows that the thermal treatment was not carried out after processing. These coins manufactured in the <i>Edo-</i>era thus had different thermal treatments.</p>

著者

花田 修治 渡辺 貞夫 佐藤 敬 和泉 修

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.45, no.12, pp.1279-1284, 1981 (Released:2008-04-04)

参考文献数

30

被引用文献数

5 8

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Magnetic heads made of Sendust alloy head cores (standard chemical composition: Fe-9.6 wt%Si-5.4 wt%Al) are known to have superior magnetic properties and wear resistance. The cores are usually made by mechanical working, such as slicing and grinding since the alloy is so hard and brittle that it has been believed to be difficult to make head cores by plastic deformation. In the present work, plastic deformability of the alloys was investigated by compressive tests on Sendust single crystals at temperatures between room temperature and 1173 K and various strain rates. Main results are summarized as follows.The operative slip systems are {110}〈111〉 and {112}〈111〉 depending on compressive axis. Therefore, the von Mises criterion for a polycrystalline material to deform plastically by slip within grains is satisfied, indicating that the brittleness of Sendust alloys cannot be explained by the number of independent slip modes available. At room temperature the stress-strain curve exhibits three stages in a similar manner to Fe3Al and Fe3Si with DO3 structure.Above the temperature where yield stress decreases abruptly, the steady state deformation takes place. Under the condition of the steady state deformation, the strain rate is represented by the relationship of \dotε=Bσnexp(−Q⁄kT), where n=4.6 and Q=540 kJ/mol. These results suggest that even a polycrystalline material of Sendust alloy may be deformable under the suitable conditions.

著者

星 恵理子 北田 正弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.67, no.7, pp.336-341, 2003 (Released:2008-04-24)

参考文献数

12

被引用文献数

4

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The effects of Cu-containing pigments on degradation of Japanese paper have been investigated. A hand-coloured wood-block print of the late Edo era is used as a naturally aged specimen. To clarify the degradation mechanism, sheets of modern Japanese paper painted with powdered malachite are aged in an environment of 353.15 K(80°C), 65%RH. Pigments are examined with XRD. Degradation of the paper is examined with a three-dimensional fluorescence spectrometer. Cu content in the specimen is measured by ICP-AES and EDS. The Cu concentrations of the cross-sections of naturally aged specimen decrease with increasing depth. In addition, the Cu concentrations at the same depth of the artificially aged paper increase with aging. These results show that the Cu species diffuse from the right to the wrong side of the paper. Although the green pigment of wood-block print contains Cu species and As species, only the Cu species has been detected in the fiber of the degraded part of the paper. The degree of degradation of the accelerated sample painted with malachite becomes higher than that of the unpainted sample. Therefore Cu is the main species that participates in the degradation of paper. The fluorescence intensity of the papers painted with malachite decreased with increasing aging time. This result shows that diffused Cu ions make impurity levels in the band gap of cellulose.

著者

田村 元紀

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.75, no.1, pp.1-4, 2011 (Released:2011-01-01)

参考文献数

6

被引用文献数

1 1

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Functionality of element iron is reviewed from a view point of evolving earth and life. Energy conversion of oxidation-reduction reaction of iron (Fe2+/Fe3+) is important for life of some bacteria and this has been continued for more than 10 billion years. Furthermore, iron has been saving life on earth by geomagnetic properties by positioning on earth's core. This most abundant metal element iron has a lot of unique properties that can be not substituted by other elements. We have been utilizing iron-carbon materials as many kinds of tools because of those widely-controllable mechanical properties. Some of magnetic, mechanical, chemical and electric properties are well known but there may be a lot of unknown properties of element iron and iron materials. Further interdiciplinary studies are suggested.

著者

小林 宙 庄司 浩史 浅野 聡 今村 正樹

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.80, no.11, pp.713-718, 2016 (Released:2016-10-25)

参考文献数

8

被引用文献数

1 3

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MCLE (Matte Chlorine Leach and Electro-winning) process developed by Sumitomo Metal Mining Co., LTD. is well known as a unique commercial nickel refining process with high nickel recovery ratio. Two types of nickel sulfide, nickel matte and mixed sulfide (MS: mixture sulfide of nickel and cobalt), are treated in the MCLE process, and the leaching rate difference for each materials become obvious in this process. Bench scale tests had been carried out and leaching rates and activation energies of chlorine leaching reactions were identified. The nickel leaching rate of MS in chlorine leaching reaction is 60% smaller than that of nickel matte.  The nickel leaching rate difference between nickel matte and MS in chlorine leaching reaction is derived from their reaction free energy difference. The determinants of the chlorine leaching reaction rate of nickel matte and MS are respectively a chemical reaction rate and elements diffusion ratio on their surface.

著者

船川 義正

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.81, no.10, pp.447-457, 2017-10-01 (Released:2017-09-25)

参考文献数

56

被引用文献数

1 1

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The interface-precipitation has been observed as row carbide arrange since 1960’s. Whereas the interface-precipitated carbides in steels were NbC, TiC, VC and Cr23C6 in the early stage, composite TiC containing Mo and W has been also become to observe recently. Several kinds of the mechanism of the interface-precipitation have been suggested and ledge mechanism and bowing mechanism which combined interface barging and carbide precipitation are widely accepted since the mechanisms successfully explained a large amount of the experimental results. Fine interface-precipitates in low carbon steel realize high strength steel sheets, plates, bars and rods which are non-quenched and tempered. Especially, in sheet products, in which fine carbides can be easily generated, ferritic steel of 1180 MPa in tensile strength is successfully obtained by dispersing fine carbides with the diameter of several nano-meters.

著者

高橋 裕 山崎 健

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.67, no.3, pp.116-121, 2003 (Released:2008-04-24)

参考文献数

10

被引用文献数

1 1

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CO2 was absorbed into C60-C70 binary solids at room temperature using a commercially available autoclave. The solids were then immersed in liquid CO2 for 24 h at a gas pressure of 5 to 6 MPa, and the degree of CO2 storage was evaluated by infrared (IR) spectroscopy and X-ray diffraction (XRD). CO2 was detected in pure C60 by IR measurement, and the stoichiometry was estimated to be C60(CO2)0.34 based on the increase in the lattice parameter. Although no trace of CO2 storage was detected for pure C70, the addition of C70 to C60 at a mole fraction of up to 0.16 did not appreciably degrade the storage capacity of CO2 from that in pure C60. The stability of CO2 trapped in solid fullerenes is explained in terms of geometrical considerations based on hard-sphere packing at octahedral sites.

著者

沼田 泰子 首藤 文榮 野村 直之 千葉 晶彦

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.70, no.2, pp.142-145, 2006 (Released:2006-02-24)

参考文献数

9

被引用文献数

2 1

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We evaluated the biocompatibility of cobalt-29 chromium-6 molybdenum alloy by analyzing disorders of the membranes of cells of the murine fibroblast L929 line. L929 cells were incubated with 10% fetal bovine serum at 37°C for 7 days in Eagle's minimum essential medium in the presence of either an extract of this alloy, or titanium extract, or vanadium ions. No morphological changes in the cells were observed in medium containing cobalt-29 chromium-6 molybdenum alloy extract or titanium extract, but a remarkable change was observed in the medium containing vanadium ion as a positive control. From the enzyme activity of the culture supernatant we determined the amount of lactate dehydrogenase (LDH) that leaked through the cell membranes. The amount that leaked from cells incubated in the presence of either of the metal extracts or vanadium ion decreased on day 1 and then increased with incubation time from day 2 onward. There was only a small increase in leakage in the media containing the metal extracts but a marked increase in the medium containing vanadium ion. These results indicate that the cell membrane remained nearly unaffected by Co-29Cr-6Mo alloy.

著者

成島 隆 吉岡 隆幸 宮崎 英機 菅 育正 佐藤 進 米澤 徹

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.76, no.4, pp.229-233, 2012 (Released:2012-04-01)

参考文献数

14

被引用文献数

5 7

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Non-oxidized metallic copper particles were prepared by plasma irradiation into aqueous solution of cupric sulfate in the presence of gelatin as a protective agent using home-made microwave induced plasma equipment. Then, two different steric structures of ascorbic acid, L-ascorbic acid and isoascorbic acid, were added as reducing auxiliaries. In the case of isoascorbic acid addition, metallic copper particles were obtained by plasma irradiation within about 5 minute. This result suggests that the reduction of copper ion from Cu2+ to metallic Cu can be succeeded by hydrogen radical generated by plasma in water combination with isoascorbic acid, and without toxic chemical agent such as hydrazine. Additionally, the diameter of copper particles can be controlled by the mount of CuSO4•5H2O and gelatin. These results were indicated that the plasma in liquid process has possibilities for high-speed and low environmental load process to prepare metallic copper particles.

著者

齋藤 繁 林 重成 成田 拓郎 加藤 泰道 大塚 元博 荒 真由美 成田 敏夫

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.83, no.10, pp.372-377, 2019-10-01 (Released:2019-09-25)

参考文献数

11

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A diffusion-barrier coating layer (DBC) was formed on a Ni-22Cr-19Fe-9Mo alloy by Al-pack cementation at 1000℃ followed by heat treatment at 1100℃.The thermal cyclic oxidation behavior of the DBC system was then investigated. The thermal cycle oxidation tests were conducted at 1100℃ in air for 45 min, each followed by 15 min at room temperature. Electron probe micro-analysis (EPMA) was performed to determine the microstructure and concentration profile of each element between the substrate and the coating layer.The DBC system showed good thermal cycle oxidation property. The layer structure between the substrate and the coating layer after thermal oxidation cycling is discussed with respect to the composition paths plotted in the Ni–Cr–Fe and Ni–Cr–Al phase diagrams. The coating layer structure after 100 cycles of 45 min at 1100℃ consisted of the γ- and α-phases of the Ni–Cr–Fe system and the β-phase of the Ni–Cr–Al system. The coating layer structure after 400 cycles of 45 min at 1100℃ consisted of the γ-phase of the Ni–Cr–Fe system and the β-phase of the Ni–Cr–Al system. In contrast, the coating layer structure after 900 cycles of 45 min at 1100℃ consisted of the γ-phase of the Ni–Cr–Fe system.

著者

小山 敏幸

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.73, no.12, pp.891-905, 2009 (Released:2009-12-01)

参考文献数

50

被引用文献数

3 8

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The phase-field method has recently been extended and utilized across many fields in materials science. Since this method can systematically incorporate the effect of coherent strain induced by lattice mismatch and applied stress as well as external electric and magnetic fields, it has been applied to many material processes including solidification, solid-state phase transformations and various types of complex microstructure changes.    In this paper, firstly the calculation method of phase-field approach is briefly explained. In particular, the basic philosophy of phase-field simulation is mentioned. Secondly, we summarize the recent calculation results of the phase-field simulation of phase transformations in Fe-based alloys and Ni (or Co)-based superalloys. Finally, the image-based calculation of materials properties is explained, where the simulated microstructure image that is the output data of phase-field simulation is employed as a boundary condition for calculating the materials property, and we show the cases of the mechanical property (stress-strain curve), magnetic property (ferromagnetic hysteresis) and electric property (ferroelectric hysteresis) as typical examples of this approach.