巻号一覧
47 巻, 5 号
選択された号の論文の12件中1～12を表示しています
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太田 陸奥雄, 金谷 輝人, 榊原 精1983 年 47 巻 5 号 p. 375-381
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーDilute Al-Zn alloys (mainly 4 mass%) quenched under various conditions were studied by careful measurement of electrical resistivity. In order to compare the results for different quenching conditions correctly, one and the same specimen was used repeatedly throughout the experiments for the same aging temperature. Intensities of SAXS were also measured. Results obtained are as follows. (1) When the aging temperature was fixed, the quasi-equilibrium resistivity, ρE, increased with the quenching temperature, TQ. Guinier radius, RG, became smaller as ρE became larger when TQ≤773 K, while the integrated intensity remained constant. (2) For TQ≥823 K, RG at the stage of ρE was about 1.15 nm irrespective of the aging and quenching temperature and was a little larger than that at the stage of maximum resistivity. (3) When ρE’s were plotted against ρ0’s (as-quenched resistivity) for a fixed aging temperature, instead of plotting against TQ, ρE relates to ρ0 regularly. ρE’s depend on ρ0’s linearly with large slope in the region of lower ρ0 (lower TQ), on the other hand, with small slope in the region of higher ρ0 (higher TQ). (4) In case of TQ≤673 K, ρ0 increased with increasing quenching speed and ρE increased with ρ0, that is, with increasing quenching speed. (5) On the other hand, when TQ≥773 K, ρ0 increased with decreasing quenching speed, while ρE increased with ρ0. ρE values corrected for the contribution of secondary defects were almost independent of ρ0 when aged at 263 K, but when aged at 233 K, ρE’s depend upon ρ0’s even at higher TQ.抄録全体を表示PDF形式でダウンロード (1201K) -
岩本 信也, 梅咲 則正, 土肥 健二1983 年 47 巻 5 号 p. 382-389
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーRaman spectra for Li2O·2SiO2 glass and melt at different temperatures were measured by using the high temperature Raman spectroscopic technique. Raman spectra observed in the frequency range from 800 to 1200 cm−1 consist of three Raman bands near 940-950, 1000-1010 and 1050-1080 cm−1. These bands are attributed to the Si-O stretching vibrations of SiO32− chain, SiO20 three-dimensional network and Si2O52− sheet silicate anions with two, zero and one non-bridging oxygens per silicon atom, respectively. The fractions of the three silicate anions in Li2O·2SiO2 glass and melt were calculated from the area intensities of the three bands. Above the glass transition temperature Tg the fraction of Si2O52− was decreased with increasing temperature, whereas the fraction of SiO32− was increased. However, there is only little difference between the Raman spectra of glass and melt, so that it is suggested that the glass structure is roughly similar to the corresponding melt structure. Furthermore, the coordination numbers of the nearest neighbour correlations Si-Si, O-Si and O-O in Li2O·2SiO2 glass and melt were estimated from the fractions of the three silicate anions, and were in good agreement with the values in Li2O·2SiO2 crystal.抄録全体を表示PDF形式でダウンロード (1125K) -
山脇 道夫, 米岡 俊明, 菅野 昌義1983 年 47 巻 5 号 p. 389-397
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーOxidation behaviour of vanadium-chromium alloys containing 5 and 10 at% chromium has been investigated at temperatures ranging from 800 to 993 K and at oxygen pressures of 1.33 and 133 Pa by means of a thermo-electrobalance, an X-ray diffractometer, an electron probe microanalyzer, a micro-hardness tester as well as metallographic techniques. Whereas mass gain due to oxidation initially followed the parabolic rate law, it then turned into very slow linear kinetics. Consequently, the oxidation resistance of vanadium was highly improved, especially at lower temperatures, lower oxygen pressures and higher chromium concentrations. Both alloys exhibited similar oxidation kinetics and scale structures. The oxide scale consisted mostly of a monolayer of VO2 of low chromium content (≤0.65 mol% Cr2O3) except for the oxidation at 993 K and 133 Pa. A very thin chromium-concentrated layer (≤0.2 μm) was formed at the oxide scale-alloy substrate interface, to which could be attributed the retarded diffusion of vanadium into the oxide scale as well as that of oxygen into the substrate.抄録全体を表示PDF形式でダウンロード (2076K) -
向井 楠宏, 岩田 章, 原田 力, 吉富 丈記, 藤本 章一郎1983 年 47 巻 5 号 p. 397-405
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーDirect observation has been performed in order to elucidate the local corrosion phenomena of solid oxides at the surface of liquid slags by dipping transparent fused silica rods or rectangular prisms vertically and partially in PbO-SiO2 slags in the temperature range from 1023 K to 1173 K in Ar atmosphere. Results obtained are as follows: (1) The major part of the local corrosion zone appears above the horizontal surface of the melts. A slag film creeping up along the surface of the silica specimen from the bulk slag moves actively in the local corrosion zone. The film thickness is below about 300 μm and it changes with changing location in the local corrosion zone. (2) Shape of the local corrosion zone changes with time, and the shape of the rod specimen differs from that of the prism specimen. (3) Linear loss of the specimen, Δds-g, at the most corroded portion in the local corrosion zone increases with time, showing wave-like curves except for the early stage of the corrosion at the corner of the prism specimen. Ranges with steep and gentle slopes of the curve correspond with the periods of the specimen with thin and thick slag films at the most corroded portion in the local corrosion zone, respectively. The rate of corrosion, dΔds-g/dt, increases with increasing temperature and PbO content of the slag. dΔds-g/dt for the prism specimen is larger at the corner of the specimen than at its plane. For the rod specimen, it increases with decreasing initial diameter of the specimen. (4) The mechanism of the local corrosion for the present system has been estimated qualitatively from the standpoint of interfacial turbulence of creeping up slag film along the specimen.抄録全体を表示PDF形式でダウンロード (2393K) -
亀田 和夫, 吉田 芳男, 坂入 専司1983 年 47 巻 5 号 p. 406-412
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe emf of a galvanic cell involving fused salt electrolytes has been measured, in order to obtain thermodynamic data of the liquid Ag-Tl system for NTl=0.231-0.850 in the temperature range from 938 to 1131 K.
The concentration dependence of activities of both thallium and silver shows a positive moderate deviation from the Raoult’s law. Our data for thallium do not agree with the result by Desré et al. but do well with that by Terpilowski et al.
The order of magnitude of both activities and heats of mixing of IB metals (Cu, Ag and Au)-thallium binary alloys in the intermediate composition range is the same as that in the Periodic Table (i.e., Cu, Ag and Au).
The activities and the heats of mixing of the liquid Cu-Tl and Ag-Tl alloys are respectively quite different from those of the liquid Au-Tl system, in which the activities show negative moderate deviations and the heats of mixing are slightly exothermic in the whole concentration range, owing to the larger electronegativity factor in the gold alloys.
Furthermore, results of both activities and heats of mixing measurements in the liquid binary alloys composed of IB metals and thallium, lead, bithmuth and those composed of IB metals and other normal metals (i.e., Zn, Cd, Al, Ga, In, Sn and Sb) have been compared and discussed in connection with the electronic structure of the elements and with the alloy theory by Engel concerning the phase stability of solid solution between IB metals and normal metals.抄録全体を表示PDF形式でダウンロード (1077K) -
西村 六郎, 荒木 道郎, 工藤 清勝1983 年 47 巻 5 号 p. 413-419
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe anodic behavior and selective dissolution of SUS304 and SUS316 austenitic stainless steels were investigated as a function of potential in a 1 kmol·m−3HCl solution by using electrochemical technique and Inductively Coupled Plasma Emission Spectrometry (ICP).
On the basis of the comparison between the amount of total anodic charge passed and that of electric charge obtained from dissolution, it was found that the anodic polarization curves of SUS304 and SUS316 were divided into three regions, the active dissolution, the film formation, and the film destruction. The compositions of metal ions dissolved in the solution revealed that the preferential dissolution of Fe took place on both steels in the active dissolution region and led to the enrichment of Cr on SUS304 surface and that of Cr, Ni and Mo on SUS316 surface. In the region of the film formation, it was found that a film formed on SUS304 was enriched with Cr because of the preferential dissolution of Fe. In the case of SUS316, it was suggested in terms of the preferential dissolution of Ni and Mo that a film changed from Cr, Ni, Mo-rich layer into Cr-rich layer during anodic oxidation.
It was, furthermore, deduced that Mo lowered the activity or density of active centers such as MnS on SUS316 surface in the process of active dissolution and consequently contributed to the formation of a uniform film free from defects.抄録全体を表示PDF形式でダウンロード (928K) -
矢作 政隆, 後藤 和弘1983 年 47 巻 5 号 p. 419-425
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe electrical conductivity has been measured at temperatures of 1173 K to 1773 K on the sintered AlN-Y2O3 and AlN-Al2O3 systems. The electrical conductivity was independent of nitrogen pressure of 5×103−105 Pa at 1473 K and 1673 K. The results on the d-c polarization and the EMF of the galvanic cell using AlN as the solid electrolyte are suggesting the predominant ionic conduction. In the experimental temperature range, the specific conductivity can be expressed as follows:
\ oindentFor AlN-2 mass%Y2O3
(This article is not displayable. Please see full text pdf.)
\ oindentwhere the activation energy is 169±5 kJ/mol.
AlN-2 mass%Al2O3
(This article is not displayable. Please see full text pdf.)
\ oindentwhere the activation energy is 200±3 kJ/mol.抄録全体を表示PDF形式でダウンロード (825K) -
中橋 昌子, 小松 周一, 中村 新一, 山田 政之1983 年 47 巻 5 号 p. 426-431
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーStudies on 12Cr-Mo-V-W steel for steam turbine blade show that the Fe2Mo intermetallic compound, so called Laves phase, is precipitated at grain boundaries after long time heating. The composition of the Laves phase in this steel having internal lattice defects is expressed by the formula (Fe25Cr7)2(Mo20W12) and is unchanged after long time heating. The M23C6-Laves phase transformation appeared to occur in situ, and the growth rate for the Laves phase during heating was larger than that for M23C6. The Laves phase area fraction was directly proportional to the Larson-Miller parameter (P=T(C+logt)×0.001) in the 23-23.5 range.抄録全体を表示PDF形式でダウンロード (1993K) -
張 栄武, 越後谷 淳一, 須藤 一1983 年 47 巻 5 号 p. 432-438
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThermal stability in microstructure as well as static and creep rupture strengths of directionally solidified Ni-Al-Ti eutectic alloys for high temperature use were investigated; the dislocation substructure in ruptured specimens was observed by means of transmission electron microscopy. Results obtained are as follows:
(1) The oriented structure of γ and γ′ phases, so-called “DS” structure was fairly stable in the temperature range below 1273 K, but it was disintegrated at higher temperatures. The more the γ content was, the more stable the DS structure was.
(2) DS structure was disintegrated rapidly by thermal cycling.
(3) Static tensile strength showed a maximum value at temperatures ranging between 973 K and 1173 K, and decreased rapidly at higher temperatures. γ fibres were broken by tension at temperatures below 1173 K, but they were elongated with matrix at 1373 K.
(4) DS structure was disintergrated during creep at higher temperatures than 1273 K.
(5) It was considered from the above-mentioned results that the temperature range for use of these alloys was limited below 1273 K, but the rupture strength of the present alloy (L: 80.5 at%Ni-11.0 at%Al-8.5 at%Ti) was superior to that of a Jackson’s alloy.
(6) Characteristic dislocation substructures in specimens subjected to creep were observed.抄録全体を表示PDF形式でダウンロード (4631K) -
増本 量, 沢谷 昭八, 比内 正勝1983 年 47 巻 5 号 p. 439-445
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe damping capacity and the anodic polarization behaviour in a 3%NaCl solution were studied on Fe-Mo-Cr alloys containing 1-16%Mo and 2-35%Cr after various heat-treatment. Measurement of the internal friction Q−1 was carried out by the inverted tortion pendulum method at a frequency of 1 Hz. The tensile strength σt and the pitting potential Ep were measured using an Instron-type testing machine and a potentiostat, respectively.
In the state of furnace-cooling, the Q−1 value of the Fe-Mo-Cr alloys with small amounts of Mo and Cr is considerably high, while the alloys with large amounts of Mo and Cr are low in Q−1 because the intermetallic compounds precipitate in the ferromagnetic α phase matrix. On the other hand, the numerous alloys subjected to water-quenching are fairly high in Q−1 because of the single phase α solid solution.
The σt in both the states increases considerably with increasing Mo and Cr contents. The increment in σt upon furnace-cooling is more than that in the case of water-quenching.
The Ep value of the furnace-cooled alloys is generally low, while the numerous alloys become higher in Ep by water-quenching where high Q−1 value appears.抄録全体を表示PDF形式でダウンロード (908K) -
内田 熊男, 姜 文圭, 藤 堅正, 井本 正介1983 年 47 巻 5 号 p. 445-449
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe titanium-nitrogen-hydrogen system has been studied by X-ray diffraction analysis and hydrogen analysis of specimens prepared by the reaction of nonstoichiometric titanium nitrides with hydrogen under a pressure of 6 MPa at 873 K. In the specimens with nitrogen to titanium ratio less than 0.5, a ternary hcp compound was formed by absorption of hydrogen. The ternary compound had a wide range in both hydrogen and nitrogen contents and is considered as α-Ti dissolving hydrogen and nitrogen. It is concluded that the solubility of hydrogen in Ti is much increased by nitrogen dissolution.
For the specimens with nitrogen to titanium ratio more than 0.6, the crystal structure remained unchanged after the hydrogenation, and the amount of hydrogen absorbed was considerably lower than that in the hcp ternary compund. The maximum solubility of hydrogen was found to be limited by (N+H)/Ti=0.9, approximately.
The enthalpy of the reaction producing the hcp ternary compound from hypostoichiometric TiN was determined by measuring hydrogen equilibrium pressures at various temperatures. The value was −66.15 kJ/mol.抄録全体を表示PDF形式でダウンロード (710K) -
草開 清志, 今井 克哉1983 年 47 巻 5 号 p. 450-456
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーIn order to elucidate the coarsening process of the dendrite structure during isothermal holding in the liquid-solid region, in situ observation was carried out.
Results obtained are as follows:
(1) It is possible to estimate a dendrite structure in a bulk from that on a surface, because both the dendrite arm spacings are almost similar.
(2) It was confirmed by the direct observation that the coarsening occurred due to the disappearance of smaller arms and the melting off of arms in a necked region.
(3) In the case of a small cylindrical arm, the coarsening of dendrite structure is explained by Model I proposed by Kattamis et al.
(4) In the case of melting off of dendrite arm in the necked region, the coarsening of dendrite structure is not explained by Model II proposed by Kattamis et al. A new model based on the kinetics of sintering of powder was proposed for this case.抄録全体を表示PDF形式でダウンロード (1456K)
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