巻号一覧
44 巻, 9 号
選択された号の論文の17件中1～17を表示しています
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浅山 行昭1980 年 44 巻 9 号 p. 963-972
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリー18%Ni maraging steels containing 1.4% or more Ti were found to show delayed failure exhibiting intergranular fracture during loading on notched specimens aged at temperatures below 770 K. The maximum sensitivity of the delayed failure was obtained at an aging temperature of 690 K. It was estimated that Ti-related precipitates, which are very sensitive to delayed failure, were produced along the pre-austenite grain boundaries during aging. The aging reaction activation energy to promote delayed failure was calculated to be 250 kJ/mol.
On the other hand, the embrittlement characterized by transgranular quasi-cleavage fracture occurred when aged at temperatures below 770 K, quite independently of the aging reaction promoting the delayed failure.
Embrittlement did not occur when aged at temperatures above 770 K. However, embrittlement did occur when specimens were re-aged at temperatures below 770 K, after pre-aging at higher temperatures. In this case, intergranular cracking due to the delayed failure did not proceed.
The activation energy determined from the embrittlement behavior by re-aging was 180 kJ/mol. This value conformed with that of the low temperature aging reaction, estimated from the change in electrical resistivity. Therefore, it was likely that the embrittlement was closely related to the precipitation of low temperature aging.
However, even when aging was performed above 770 K, the embrittlement showed a tendency to increase with aging time.
It is concluded that the cause of embrittlement is due to an increase of the transition temperature brought about by precipitation depletion of Ni and/or Mo in the matrix.抄録全体を表示PDF形式でダウンロード (1400K) -
田中 志津子, 神沢 康夫1980 年 44 巻 9 号 p. 973-979
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーCu-Pd-Ag alloys were aged with the isochronic ageing method after quenching from the solid solution temperature into ice water. The hardness test, electrical resistivity measurement and X-ray diffraction analysis were performed to investigate the ageing characteristics. It was found that there were three different hardening stages. They were “Stage I” supposed to be caused by short range ordering in the matrix phase, “Stage II” by fine precipitates of the α2 phase, and “Stage III” by precipitation of the β phase which is a long range ordered phase of the Cu-Pd system and of the α2 phase. In the alloys of lower Ag content, “Stage II” was absent.抄録全体を表示PDF形式でダウンロード (547K) -
田中 志津子1980 年 44 巻 9 号 p. 979-988
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーCu-Pd-Ag dental base alloys which contain 0∼7.7 at%Ag were aged isothermally at various temperatures between 523 and 773 K after quenching from the solid solution temperature into ice water. The hardness test, electrical resistivity measurement, X-ray diffraction analysis and optical microscopic observation were performed to investigate the ageing process of the alloys. It was found that the hardness of the aged alloy was dependent mainly on the β phase which was precipitated in the α1 phase matrix. The decreasing part of the electrical resistivity curve of the aged alloy fitted to the Johnson-Mehl equation, where two stages with the time exponents n\fallingdotseq2.7 and n\fallingdotseq0.9 were revealed. The estimated activation energy for the first stage corresponding to the precipitating stage of the β phase was 138∼160 kJ/mol.抄録全体を表示PDF形式でダウンロード (1700K) -
雄谷 重夫, 鞘師 守1980 年 44 巻 9 号 p. 989-998
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーSolute behavior of alloys at the latter stage of solidification and immediately after its completion was discussed by holding Cu-8 mass%Sn alloy specimens isothermally in liquid-solid, non-equilibrium liquid-solid and non-equilibrium α+β states. At high fraction solid (higher than 0.85), dendrite arm coarsening was strongly affected by the diffusion in solid. The disappearance of the unstable phase and coring in α-dendrites were observed at any temperature below the equilibrium solidus. The largest homogenizing rate was obtained at just above the peritectic isotherm. This phenomenon was thought to result from the large solubility, fast interdiffusion and the liquid second phase or spherical second phase particles.抄録全体を表示PDF形式でダウンロード (1141K) -
雄谷 重夫, 鞘師 守, 福原 由雄1980 年 44 巻 9 号 p. 998-1006
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe non-equilibrium peritectic transformation of Cu-Sn alloys was verified by experiment and calculation assuming a diffusion controlled thickening process of the peritectic β-phase. The unstable liquid and the α-solid solution remain in the hypo- and hyper-peritectic alloys respectively, when cooled down to just below the peritectic isotherm. The fact shows occurance of the non-equilibrium peritectic transformation. The rate of peritectic β-phase thickening by diffusion in the β-phase increases with undercooling from the peritectic isotherm 1072 K during holding at the temperature between two peritectic isotherms (1072 and 1029 K) and with the cooling rate during continuous cooling. If the peritectic β-phase to be formed is of large thickness or the cooling rate is great, solidification of Cu-Sn alloys completes with direct crystallization of secondary β-phase from super-cooled liquid at the later stage of solidification.抄録全体を表示PDF形式でダウンロード (1357K) -
横田 勝, 野瀬 正照, 三谷 裕康1980 年 44 巻 9 号 p. 1007-1012
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe interdiffus on coefficients (\ ildeD) in the β and γ phases of the Cu-Sn binary alloy system were determined by the Boltzmann-Matano method in the temperature range between 874 and 993 K using the diffusion couples consisting of pure copper and γ (Cu-16.9∼17.9 at%Sn) alloys. \ ildeD increased with tin content in the β phase, while it decreased remarkably with tin content in the γ phase except for the temperature at 874 K; \ ildeD at this temperature only did not have concentration dependence. On the other hand, the intrinsic diffusion coefficients (DCu and DSn) were calculated by using Darken’s method, where the Kirkendall markers were observed to move toward the copper-rich side, and the chemical composition at the Kirkendall marker was Cu-14.5 at%Sn.
The temperature dependences of \ ildeD, DCu and DSn at the above chemical composition were given by
(This article is not displayable. Please see full text pdf.)
\ oindentso that it was considered that the copper atom diffused faster than the tin atom at the Kirkendall marker position.
The expansion of diffusion couples after diffusion annealing has been concluded to originate mainly from the Kirkendall effect, although the change of molar volume cannot be neglected.抄録全体を表示PDF形式でダウンロード (749K) -
古賀 秀人, 内山 休男, 安芸 隆房1980 年 44 巻 9 号 p. 1012-1018
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーIn order to study the effect of alloying elements in steel on the Fe-Zn reaction, commercial carbon steels were immersed into pure molten zinc for 60∼6000 s at 713∼873 K. The alloy layers formed on the steel surface were observed and the quantities of iron reacted with zinc were measured. The results are as follows:
(1) At 713 K, the alloy layers consisted of Γ, δ1, (δ1+η) and ζ. The ζ was the aggregate of fragmented ζ crystals, and this phase dropped off into η for immersion longer than 3000 s. Up to 763 K, ζ was also formed, but it grew to a large columnar crystal. Above 773 K the alloy layer sequence was similar to that of pure iron samples.
(2) Although Fe3ZnC was formed, the sequence of the alloy layer formed on the pearlite was identical to that formed on the ferrite.
(3) FeSi was formed in the alloy layer, but it could not be found under the optical microscope.
(4) The δ1 thickness-temperature curves had two peaks at 733 and 813 K. The fact that the surface of δ1 was covered entirely by ζ caused the peak at 733 K. The peak at 813 K was due to δ1K formation and a drop off into η.
(5) The temperature dependence of iron loss corresponded to that of iron quantity remained in the alloy layer up to 763 K, and to that of iron quantity dissolved into the zinc bath above 813 K.抄録全体を表示PDF形式でダウンロード (994K) -
内山 休男, 古賀 秀人1980 年 44 巻 9 号 p. 1018-1024
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーIn order to study the effect of heat treatment of steels on the Fe-Zn reaction, carbon steels heat treated in three different conditions were immersed into pure liquid zinc for 60∼600 s at 733 K. Alloy layers formed on the steel surface were observed and the quantities of iron reacted with zinc were measured. A eutectoid steel with pearlitic structure was also immersed into pure molten zinc in order to clarify the effect of pearlite on this reaction. The results are as follows:
(1) Heat treatment conditions did not affect the iron loss after immersion shorter than 120 s. On the other hand, the iron loss after 600 s immersion decreased when the aging temperature exceeded 873 K.
(2) The temperature dependence of iron loss corresponds to the residual stress for S10C samples.
(3) On steels containing carbon and silicon a columnar ζ crystal was formed. The growth rate of this phase was in propotion to immersion time. Between the individual ζ crystals there was the η phase.
(4) When a eutectoid steel with pearlitic structure was immersed into liquid zinc at 733 and 773 K, the steel/Fe-Zn alloy interface was irregular.抄録全体を表示PDF形式でダウンロード (1048K) -
曾我部 卓三, 堀 茂徳1980 年 44 巻 9 号 p. 1024-1031
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーContinuous and discontinuous precipitations were investigated for a Cu-26Ni-8Fe alloy aged isothermally in the temperature range of 673 to 1023 K, by means of optical and electron microscopic observations, hardness measurement and X-ray diffraction analysis. The results obtained are as follows:
(1) During the earlier ageing stages, wavelength of the modulated structure remained a constant value (8∼9 nm) and then increased the (time)1⁄3 law.
(2) Discontinuous precipitations were observed when the specimens were aged in the temperature range of 673 to 853 K. The growth rate of it greatly decreased with increasing temperature.
(3) Volume fraction of discontinuous precipitates, f, could be represented by Johnson-Mehl’s equation; f=1−exp(−btn), and the n-values were 1.0 at 673 K and 0.8 at 723 K. But above 723 K, this equation could not be applied during the later ageing stages.
(4) The above described temperature dependence of the discontinuous precipitation may be caused by the progress of continuous precipitation.
(5) The apparent activation energy of continuous and discontinuous precipitation process was about 188 kJ/mol and 84 kJ/mol, respectively.抄録全体を表示PDF形式でダウンロード (1121K) -
辻本 得蔵1980 年 44 巻 9 号 p. 1031-1036
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe composition variation, q(x, t) in a supersaturated solid solution of average composition, c0, is written as
(This article is not displayable. Please see full text pdf.)
\ oindentThe composition variation peak at x=0 conforming to the conditions, qx=0>0, (∂q⁄∂x)x=0=0 and (∂2q⁄∂x2)x=0=−β2∑hh2Q(h)<0, rises by diffusion if −\ ildeDx=0>0. \ ildeDx=0 is an interdiffusion coefficient of composition at x=0. When the gradient energy is taken into consideration, this condition is given by
(This article is not displayable. Please see full text pdf.)
\ oindentHere ψ=−2kβ2[∑hh4Q(h)⁄∑hh2Q(h)]k is (gradient energy coefficient)×(mobility of atoms).
The function, Q(h), is a Fourier spectrum which represents the composition variation. An initial Fourier spectrum, Qi(h), chosen arbitrarily changes to spectra, Qd(h), with amplification of composition variations by diffusion, and then to spectra Qa(h). In Qd(h)Q(h)>0 for all h when the composition variation peaks defined above are formed, and in Qa(h) the sings of Q(h) alternate with increasing h. Thus, ∑hh4Q(h)>0 for Qd(h) and ∑hh4Q(h)<0 for fully developed Qa(h). In low solute alloys Qd(h) develops highly, hence the formation of Qa(h) is retarded. In high solute alloys well-developed Qd(h) is not formed. This difference of spectra determined whether eq. (2) holds or not.
In the alloy system whose spinodal compositions are 0.24 and 0.76, amplification processes of composition variations which have the largest peak at x=0 are simulated by the computer. In alloys of c0>0.15, ψ turns out to be positive before c0+qx=0=0.76 has attained, and the composition peak reaches an equilibrium composition by virtue of ψ. In alloys of c0<0.15 the composition peak diminishes even in the composition range of −\ ildeDx=0>0 as a result of the decrease in ψ.抄録全体を表示PDF形式でダウンロード (471K) -
清重 正典, 立助 正一1980 年 44 巻 9 号 p. 1037-1045
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe effect of working temperature before annealing on the recrystallization of Ni-30%Cu alloy was investigated by Vickers hardness measurement, optical microscopy and transmission electron microscopy. As the working temperature increased, the beginning of recrystallization was retarded and the grain size of recrystallized structure became finer. However, the activation energy for recrystallization was not affected so much by the working temperature, except for room temperature. Finer recrystallized grains were obtained at a higher working temperature and a lower annealing temperature. It is considered that the refinement of structure due to warm working is attributed to the dislocation cell structure.抄録全体を表示PDF形式でダウンロード (1829K) -
市村 稔, 今林 守1980 年 44 巻 9 号 p. 1045-1052
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーA melt of pure aluminum (99.99 mass%) was held in air and treated in three different ways. One way was to stir the melt by an alumina tube, and the other two ways were to blow the air into the melt for 300 and 600 s respectively. The treated melt was cast in a metal mold. The diffusion coefficient (D) and the solubility (S) of hydrogen in the specimens cut out from the ingots were measured by the vacuum solid extraction method. The results were compared with the authors’ previous result and the following conclusions were derived.
The hydrogen content, oxide content and total void volume in the specimen were increased by stirring or air blowing in the melt. In the specimen melted in air and solidified in metal mold, D decreased and S increased as compared with the specimen melted in vacuum and solidified unidirectionally. The decrease of D and the increase of S became more remarkable by stirring or air blowing.
The changes of D and S were well interpreted by trapping of hydrogen by the gas voids formed by contact of the melt with air.
The differences in the total volume of voids in the specimens may be the most probable cause for the large scattering of the values of the diffusivity of hydrogen in solid pure aluminum reported by other investigators.抄録全体を表示PDF形式でダウンロード (1052K) -
岸本 誠, 泉 久年, 森 克巳, 川合 保治1980 年 44 巻 9 号 p. 1053-1059
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーMeasurements of interfacial tension in the systems Fe-SiO2 and Fe-Al2O3 were made at 1873 K by use of the sessile drop method. In Fe-SiO2 from the interfacial tension isotherm as a function of oxygen activity, excess oxygen concentration in the interface was calculated to be 1.39×10−5 mol/m2. From this value it was shown that the interface consists of a FeO monolayer. Under the condition where the reaction Si+2O=SiO2 takes place, the interfacial tension between molten iron and a sintered silica substrate was high but lowered conciderably in several minutes. This was due to the fact that the interface was composite and that the precipitated liquid silica was accumlated at the edge of the drop. In the Fe-Al2O3 system the interfacial tension apparently increased when alumina precipitated at the interface.
Observations of many investigators that the interfacial tension falls abnormally at the initial stage of the progress of reaction were interpreted in terms of the Marangoni effect. It was shown that the interfacial tension in nonequilibrium system is not associated directly with the transfer rate of components but is dependent on the chemical potentials, especially of oxygen, at the interface.抄録全体を表示PDF形式でダウンロード (626K) -
宮城 政和, 佐藤 幸弘, 水野 利昭, 沢田 重政1980 年 44 巻 9 号 p. 1060-1068
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーVarious kinds of treatment such as ion-etching, filling with diamond, dipping into mixed acid (HF:HNO3=1:3), anodic oxidation and dry-oxidation in air were used for the surface preparation of pure titanium, Ti-0.16%Pd, Ti-5%Ta, Ti-15%Mo-0.2%Pd and Ti-8%Mn alloys, and characterization of their surfaces was investigated by ESCA. The results obtained were as follows:
(1) The ESCA spectrum of Ti2p3⁄2 obtained from pure titanium which was filed with diamond consisted of four components TiO2, Ti2O3, TiO and metallic Ti, and the higher oxidation states predominated on the outer surface of the oxide film. ESCA data also showed that the alloying elements were present in different valent states such as oxide, suboxide and metal, of which fractions depended on the way of surface treatment.
(2) In titanium and titanium alloys filed with diamond, titanium nitride was formed on the surfaces, whereas no nitride was formed when abrased with emery paper in running water.
(3) In titanium ion-etched with Ar ions, titanium carbide was formed on the surface due to the reaction with contaminated hydrocarbon and no clean titanium surface, therefore, was obtained by ion-etching.
(4) In Ti-0.16%Pd and Ti-15%Mo-0.2%Pd alloys dipped into mixed acid, the surface enrichment of the alloying elements was observed; in the former palladium was enriched in the metallic state, whereas in the latter molybdenum was enriched in the oxidation state, but no Pd3d peak was observed.
(5) In Ti-0.16%Pd, Ti-5%Ta and Ti-15%Mo-0.2%Pd alloys oxidized in air at 673 K for 600 s, the titanium oxide TiO2 was present on outermost surfaces of the specimens, whereas in the Ti-8%Mn alloy the enrichment of manganese in the oxidation state was observed on the outer surface.抄録全体を表示PDF形式でダウンロード (707K) -
植田 幸富, 小野 勝敏, 森山 徐一郎1980 年 44 巻 9 号 p. 1069-1075
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe carbothermic reduction-electron beam melting combination method has made it possible to produce the pure niobium metal. In the present investigation, the relationship between the pressure, the temperature and the concentration of carbon and oxygen in the Nb-C-O solid solutions has been determined as the base for the carbothermic reduction of niobium in vacuum.
The niobium metal with arbitrary contents of carbon and oxygen was equilibrated with the CO-CO2 gas mixture of the CO2 content below 1000 ppm, at 2073∼2273 K and the reduced pressure. The reduced pressure from 0.13 to 13 Pa was realized in a vacuum furnace with a tantalum heating element by balancing the introducing rate of gas through a slow leak valve with the evacuating rate by a diffusion pump.
The thermodynamic equilibrium between the Nb-C-O solid solution and the CO-CO2 gas mixture can be described by the following equations:
(This article is not displayable. Please see full text pdf.)
The total pressure must be reduced even at the temperature as high as 2273 K and the CO2 concentration must be very small for the Nb-C-O solid solution to be stable, so that the reaction (1) is predominant and the reaction (2) may be negligible. The following expression relating the pressure, the temperature and the concentration of carbon and oxygen in niobium has been derived:
(This article is not displayable. Please see full text pdf.)
\ oindentwhere PCO is the pressure in Pa, CC and CO the atomic percents of carbon and oxygen and T the absolute temperature.抄録全体を表示PDF形式でダウンロード (548K) -
鈴木 芳春, 増本 健, 小倉 次夫1980 年 44 巻 9 号 p. 1076-1083
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーThe formation of plastic zone at the tip of fatigue cracks was studied three-dimensionally using plate samples of a Fe-3%Si alloy. The three-dimensional shape and size of the plastic zone were examined by observing the surface and the inside of the sample using an etching technique.
The main results obtained are summarized as follows:
(1) The shape and size of the plastic zone formed on the surface are different from those of the inside, because the mode of deformation changes from “plane stress” near the surface to “plane strain” inside.
(2) The relationship between plastic zone size and crack length on the surface and inside, and the effect of stress amplitude on plastic zone size are explained well by using B-C-S model modified by cyclic yield stress and plastic constraint factor.
(3) The mode of deformation near the tip of a fatigue crack is related closely to the size of the plastic zone on the specimen surface depending on specimen thickness.抄録全体を表示PDF形式でダウンロード (1224K) -
高山 新司1980 年 44 巻 9 号 p. 1084-1087
発行日: 1980年
公開日: 2008/04/04
ジャーナル フリーFabrication of round cross-sectional metallic glass wire has been reported. This wire ∼0.08 mm in diameter, has been made by drawing an as-quenched metallic glass ribbon with a composition Fe29Ni49P14B6Si2 through dies in multiple passes. Comparing with mechanical properties of an original metallic glass ribbon, fracture stresses of the wire thus made do not change significantly but the plastic strains increase remarkably.抄録全体を表示PDF形式でダウンロード (688K)
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