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

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
市川 宏 武田 道夫 瀬口 忠男 岡村 清人
出版者
公益社団法人 日本金属学会
雑誌
まてりあ (ISSN:13402625)
巻号頁・発行日
vol.39, no.2, pp.190-192, 2000-02-20 (Released:2011-08-11)
参考文献数
4
被引用文献数
3
著者
岡部 徹
出版者
公益社団法人 日本金属学会
雑誌
まてりあ (ISSN:13402625)
巻号頁・発行日
vol.56, no.3, pp.157-160, 2017 (Released:2017-03-01)
参考文献数
8
被引用文献数
1
著者
兵頭 俊夫
出版者
公益社団法人 日本金属学会
雑誌
まてりあ (ISSN:13402625)
巻号頁・発行日
vol.35, no.2, pp.103-109, 1996-02-01 (Released:2011-08-11)
参考文献数
42
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

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

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.
著者
井上 潔 島 好範
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.33, no.7, pp.755-760, 1969 (Released:2008-04-04)
参考文献数
6
被引用文献数
2

The purpose of this paper is to clarify the character of spark carburization for iron, and characteristics of the spark carburized layer which is not found in other carburizing treatments, and also to investigate the effect of superposing magnetic field and high frequency current. Through microscope and by X-ray diffraction, the following conclusions have been drawn:(1) Glycerine-25% Potassium acetate is extremely excellent for the carburizing solution, and the caburized layer of 0.2∼0.5 mm can be obtained by 5∼10 min carburization.(2) As for the structure of the carburized quenching layer, the surface shows structure including carbide, residual austenite and martensite, and moreover the inner part shows a martensite structure like fine needles. This is because the surface layer contains a large amount of carbon, and from this it can be estimated that the mechanical properties, especially wear resistance, is excellent.(3) In the carburization the high frequency current has the effect of unifying diffusion. In this case, the frequency of 350 KHz is effective. The magnetic field has the effect of increasing the carburizing ability by 50∼80% on the surface in parallel with the magnetic flux.
著者
金子 秀夫 村上 毅 池内 準
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.32, no.10, pp.982-987, 1968 (Released:2008-04-04)
参考文献数
3
被引用文献数
1 1

The process of carburization is the oldest and has been most extensively employed in industry as a method of case hardening of steels. The progress in the carburization technique, however, has not been extremely rapid. Therefore a new method with higher rate of penetration and better quality of case is extensively craved for. To find a solution of this problem, electrodischarge carburization has been conducted by the present authors to combine electrodischarge heating and the carburizing action in a special electrolyte. This is a method of case hardening of steels in a electrolyte that contains the chemicals required to produce a case comparable with one resulting from liquid carburization. This provides a convenient method of carburization, with low distortion and with considerable high rate of penetration and uniformity of control of the case.The best carburizing conditions obtained in the present study are as follows:electrolyte: ethleneglycol saturated with sodiumchlorideapplied voltage: 150 V DCcarburizing time: 1∼5 mincase depth: 0.2∼0.3 mmhardness of the case: >Hv 850
著者
京武 順 武末 尚久 森永 正彦 湯川 夏夫
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.55, no.10, pp.1031-1038, 1991 (Released:2008-04-04)
参考文献数
14
被引用文献数
1 1

A first computer method has been proposed for the simulation of the local atomic displacement in alloys. Employing a Monte Carlo method the simulation has been carried out so that the local displacement parameters determined experimentally from diffuse-scattering measurements fit the simulationed ones. A whole feature of atomic fluctuations can be spacified by combining this method with Gehlen-Cohen method for the chemical short-range order in alloys.This method has been applied to the structural problem of the G.P.zones in Al-Cu alloys. There are distinctive atomic displacements inside and outside the zone. In particular, it is interesting to note that the modulated displacement-waves spread over a relatively wide region surrouding the G.P.zone.
著者
藤本 慎司 岡田 信宏
出版者
公益社団法人 日本金属学会
雑誌
まてりあ (ISSN:13402625)
巻号頁・発行日
vol.50, no.7, pp.274-278, 2011 (Released:2012-12-13)
参考文献数
49
被引用文献数
1
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
pp.J2018048, (Released:2019-03-01)
参考文献数
12

The production processes of old Japanese coins, Genbun-koban, Akita-ginban and Morioka-ginban, were studied. These coins were manufactured by a forging method in the Edo-era. Genbun-koban, manufactured at a gold mint of the Tokugawa shogunate called Kinza, 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 Iroage method was used to color the coin; it is a thermal treatment, resulting in lows the residual stress is smaller at flat area. Akita-ginban, manufactured in the Akita 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. Morioka-ginban, manufactured in the Morioka 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 Edo-era thus had different thermal treatments.
著者
片山 英樹
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.78, no.11, pp.419-425, 2014 (Released:2014-11-01)
参考文献数
25
被引用文献数
1 13

Fundamentals of an electrochemical impedance measurement were reviewed. The impedance characteristics under charge transfer control and under diffusion control, and their equivalent circuits are described. Analytical method using the Nyquist plot and the Bode plot for typical impedance spectra was explained. In addition, a change in impedance behavior for CPE (constant phase element) parameter, which is often used in equivalent circuit modeling and data fitting of electrochemical impedance data, was represented. In the latter of this paper, research reports for degradation estimation of steel materials used for infrastructure using an electrochemical impedance measurement were provided. The degradation of organic coated steels, the structure of thermally sprayed coating exposed to outdoors for a long term, and the corrosion performance of reinforcing steel bars in concrete were estimated by electrochemical impedance method.
著者
宮岡 裕樹 市川 貴之 小島 由継
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.12, pp.552-558, 2013 (Released:2013-12-01)
参考文献数
26

Hydrogen is chemically absorbed into graphite by mechanical ball-milling process under H2, and its hydrogen capacity reaches to about 3.6 mass%. Noteworthy, when iron (Fe) mingles with graphite from steel balls during the milling process, the hydrogen capacity is drastically enhanced. In this work, the hydrogen absorption and desorption properties of the hydrogenated graphite with and without Fe were investigated. The hydrogen capacity of graphite including Fe was about 6 mass% (H/C), suggesting that the excess hydrogen of 2.4 mass% would originate in the Fe related phase. It is clarified by spectroscopic studies that the mingled iron formed a non-stoichiometric iron-carbon (Fe-C) phase as hydrogen absorption site. Assuming that the Fe/C ratio is 1, its hydrogen capacity is estimated to be H/(Fe-C-H)>10 mass%, which is a larger value than that of the conventional hydrogen storage materials. The hydrogen absorbed in the C-Fe phase is released at 450℃ with the transformation of the C-Fe phase to well-ordered carbides such as Fe3C. Therefore, if the C-Fe phase could be synthesized independently, it should be recognized as a promising hydrogen storage material.
著者
殷 福星 高森 晋 大澤 嘉昭 佐藤 彰 川原 浩司
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.65, no.7, pp.607-613, 2001 (Released:2008-04-24)
参考文献数
19
被引用文献数
11 17

Control of noise and vibration remains to be solved for the lowering of environmental load in all the industrial fields. It is necessary to take account of the noise and vibration problem when designing machines or structures. Therefore the development of damping materials suitable for structural parts that are easy to process and recycle, is urgently required. Mn-Cu damping alloys show the most satisfactory mechanical properties and damping capacity among the developed damping alloys. The M2052 damping alloy, which has a nominal composition of Mn-20Cu-5Ni-2Fe (at%), shows both a high damping capacity and a high strength. The damping capacity of M2052 alloy increases to a high level below a certain temperature, and the damping level also varies sensitively to the changes in vibration frequency and strain amplitude. By the peak-shift method the thermal activation energy for the {101} twin boundaries responsible for the low-temperature damping peak is calculated to be 4.88×104 J/mol. The tensile strength of the alloy is 500 MPa, accompanied with a superior workability for practical applications. It is confirmed experimentally that M2052 damping alloy is quite effective in damping the intolerable vibrations when used as structural parts.
著者
松井 光彦
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.64, no.5, pp.403-406, 2000 (Released:2008-04-24)
参考文献数
7

Recently sodium ionic conductors such as NASICON (Na3Zr2Si2PO12) have been used as the solid electrolyte for EMF(electromotive force) type CO2 sensors. However, it has been hard to obtain a sufficiently high quality in this type of sensor, partly due to the low humidity-resistance of NASICON and partly because of its poor initial response of EMF to CO2 pressure.For the purpose of improving the humidity-resistance and the initial response of EMF of the solid electrolyte CO2 sensors, Li2TiSiO5 is employed as the sensing material instead of NASICON. It is composed of the following electrochemical cell:(This article is not displayable. Please see full text pdf.) The electrochemical reaction is in good agreement with the Nernst equation, and reacted electron is calculated as 2.04. The sensor fabricated with Li2TiSiO5 shows good linearity when it is exposed to an atmosphere of 90% relative humidity at 60°C. The initial 90% response of EMF is steadied within 4 min. These experimental results make it possible to use the sensor in the environments.
著者
土屋 正行 泉山 昌夫 今井 勇之進
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.29, no.4, pp.427-433, 1965 (Released:2008-04-04)
参考文献数
24
被引用文献数
2 12

The investigation on the transformation of austenite to martensite based on the statistical thermodynamics was carried out using the iron-nitrogen binary alloys containing about 1.8 to 2.8 weight per cent nitrogen. The result of this treatment was compared with that of the iron-carbon binary alloys. The Ms point which was determined microscopically by the Greninger and Troiano method descends with the increase of the nitrogen content and attains room temperature at about 2.2 weight per cent nitrogen showing a complete austenitic structure. Ms points of the iron-nitrogen and iron-carbon alloys containing the same atomic percentage agreed with each other. The T0γ−α′ temperature (ΔFγ→α′=0) of the iron-nitrogen alloy fell nearly parallel to the change in the Ms point with increase of the nitrogen content. On the other hand, the driving force necessary for initiating the martensite transformation increased with increase of the nitrogen content. The effect of carbon on the thermodynamic properties of martensite transformation agreed with the effect of nitrogen. Stabilities of martensites and supersaturated ferrites of the nitrogen- and the carbon-iron alloys were also discussed.
著者
新里 秀平 譯田 真人 尾方 成信
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
pp.J2015061, (Released:2016-01-22)
参考文献数
25
被引用文献数
7

It is well known that the mechanical strength of iron is significantly changed by alloying. However, atomistic origin and underlying mechanism are still unclear. Since the strength change with respect to solute concentration is very sensitive and highly non-linear, the way of empirical prediction may contribute little to designing the mechanical strength by alloying. In this study, we theoretically construct a model which predicts temperature, strain rate, and solute concentration dependencies on critical resolved shear stress (CRSS) and yield stress of BCC iron alloys with dilute substitutional solutes based on atomistic analysis of the dislocation-solute atom interaction. In the coarse-grained BCC polycrystalline metals, the mechanical strength and deformation are dominated by screw dislocation motion consisting of kink nucleation and migration processes. Thus, our model is based on atomistically computed activation free energies for kink nucleation and migration of screw dislocation. We eventually apply our model to Fe-Si dilute alloy system as a representative example of BCC dilute alloys, and the theoretically predicted CRSS by our model is compared with an experimental one.