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)

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
加藤 雅治
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.47, no.5, pp.256-261, 2008-05-01 (Released:2011-08-11)
被引用文献数
1 or 0
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 or 0

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
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
(Released:2016-01-22)

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.
著者
Wang W. G. Matsugi K. Fukushima H. Sasaki G.
出版者
公益社団法人 日本金属学会
雑誌
MATERIALS TRANSACTIONS
巻号頁・発行日
vol.48, no.7, pp.1948-1954, 2007

AZ91D magnesium alloy reinforced with aluminum borate whisker (Al<SUB>18</SUB>B<SUB>4</SUB>O<SUB>33w</SUB>, denoted by ABO<SUB>w</SUB>) was fabricated by squeeze-casting. The heat treatment (T4) was carried out at 693 K in argon atmosphere for 48 and 96 hours, respectively, following water-quenched. The behaviors of interfacial reaction were studied in processes of fabrication and following heat treatment. Microstructures of interfacial reaction layers were investigated with transmission electron microscopy (TEM). Interfacial reaction layer in thickness of 5&ndash;10 nm was found in as-casted composite, and it was identified that the interfacial reaction layer was consisted of MgO. When the composite was heat-treated at 693 K for 48 hours, the surfaces of whiskers were covered with interfacial reaction layer completely and the thickness of interfacial reaction layer increased to about 20 nm. With increasing the time of heat treatment from 48 hours to 96 hours, the thickness of interfacial reaction layer on the surfaces of whiskers did not change obviously. The interfacial reaction layer was consisted of tiny MgO particles and a small quantity of MgB<SUB>2</SUB> particles. Although MgO particles played a good barrier to keep out of contacting between magnesium and whisker, the boundaries between MgO particles acted as a shortcut of magnesium atoms migration. Therefore magnesium could keep on reacting to whisker. The interfacial reaction could invade into the inner of whisker about 20 nm depth after the composite was heat-treated at 673 K for 96 hours. The surfaces of whiskers became wave-like because of interfacial reaction. An orientation relationship was found between MgO reaction layer and ABO<SUB>w</SUB>: (11\\bar1)<SUB>MgO</SUB>||(320)<SUB>ABOw</SUB> and [011]<SUB>MgO</SUB>||[001]<SUB>ABOw</SUB>. The surfaces of MgO particles were consisted of close-packed (111)<SUB>MgO</SUB> plane.
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)

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
平山 俊成 小切間 正彦
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.34, no.5, pp.507-510, 1970 (Released:2008-04-04)
被引用文献数
3 or 0

In order to investigate the martensitic transformation in Fe-Cr-Ni stainless steel, the Ni equivalent has been introduced thermodynamically as a universal quantity which indicates stability of austenite with regard to chemical composition. The relation between the Ni equivalent and the amount of strain-induced martensite or athermal martensite has been studied by means of saturation flux density measurement. Furthermore, the mechanism of the formation of strain-induced martensite has been considered thermodynamically.The results obtained are summarized as follows:(1) The Ni equivalent, (Ni), in Fe-Cr-Ni stainless steel is expressed by\phantom(1)(Ni)=Ni+0.65Cr+0.98Mo+1.05Mn+0.35Si+12.6C\ oindentwhere Ni, Cr, etc. represent weight % of these elements in the stainless steel considered.(2) The relation between the Ni equivalent and the amount of strain-induced or athermal martensite has been obtained.(3) About 75% cold rolling of Fe-Cr-Ni stainless steel has the same effect on martensitic transformation as decreasing the Ni content by 3∼5%. In this case, the difference in the free energy at room temperature between the ferrite phase and the austenite phase increases by about 113∼188 cal/mol.(4) The deduced value of the work done by transformation strain induced by the applied stress due to cold rolling is about 120∼126 cal/mol or about 192 cal/mol by compressive or tensile stress, respectively. These values agree very well with the above mentioned change of the free energy difference calculated from the variation in Ni equivalent. Therefore, under applied stress, the stored free energy required for martensitic transformation can be lowered by this work value, 120∼192 cal/mol.
著者
中村 崇 植田 安昭 Toguri James M.
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.50, no.5, pp.456-461, 1986 (Released:2008-04-04)
参考文献数
33
被引用文献数
1 or 0

A new scale of the theoretical optical basicity was established by means of the concept of the average electron density (D) expressecl in eq. (1).(This article is not displayable. Please see full text pdf.) \ oindentThe value of α in an oxide system was defined unity, and the values of α in alkaline earth fluoride and chloride systems were determined by measurments of Pbs-p spectra of CaF2 and CaCl2 using photoacoustic spectroscopy.The basicity moderating parameter values were found to have a linear relation with the values of the average electron density, as shown in eq. (2).(This article is not displayable. Please see full text pdf.) The theroretical optical basicity values of transition metal oxides were able to be calculated in the new scale, for example, ΛFeO=0.94, ΛFe2O3=0.72 and ΛTiO2=0.65. It was possible to explain the sulfide capacity values in the systems containing iron oxides using these optical basicity values. The theoretical optical basicity values of alkaline earth fluoride and chloride were also obtained in this study. The values of the optical basicity showed a good correlation to logarithmic values of the phosphate capacity at a constant temperature in the systems consisting of oxide and fluoride compounds. It is suggested that the theoretical optical basicity developed in this study was a resonable scale for a wide range basicity in slags and fluxes.
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)
被引用文献数
3 or 0

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
渋江 和久 熊谷 正樹 金 睦淳
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.56, no.12, pp.1457-1462, 1992 (Released:2008-04-04)

The oxidation property of a Ti-33.5 mass%Al-2.5 mass%Mn intermetallic compound prepared by a reactive-sintering process was studied at 1223 K in air in comparison with that by a melt process. The reactive-sintered alloy had been found to have superior oxidation resistance to the melted one. The oxidation scale of the former was suggested to be adhesive, for example, owing to the presence of fine alumina particulates and/or pores which contribute to pegs. The fine alumina particulates were developed by breaking up of the oxide layer along prior particle boundaries during the reactive-sintering process.
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)

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
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)
被引用文献数
2 or 0

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.