巻号一覧
43 巻, 10 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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菊地 紀雄, 深道 和明, 増本 健1979 年 43 巻 10 号 p. 885-890
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーAmorphous (Fe1−xCrx)85B15 Alloys (x=0∼0.15) were prepared from the melts by rapid quenching using a single roller technique, and their Invar and Elinvar characteristics and corrosion resistance were investigated. With an increase in chromium content, the Curie temperature and the saturation magnetic moment per iron atom decreased monotonically, while the crystallization temperature increased gradually. The thermal expansion coefficient α around room temperature became slightly larger with increasing chromium content. Nevertheless, these amorphous alloys exhibited excellent Invar characteristics below the Curie temperature. The value of Young’s modulus increased remarkably in a relatively low magnetic field and then saturated at a field of about 80 kA/m, showing a large ΔE effect. Its value as well as a longitudinal linear magnetostriction became smaller with increase in chromium content. The temperature coefficient of Young’s modulus changed from positive to negative, and the temperature range showing the Elinvar characteristics became narrower with chromium content. The temperature coefficient of delay time determined from the values of α and e was very small. The corrosion resistance of these alloys was extremely improved by chromium addition.抄録全体を表示PDF形式でダウンロード (485K) -
牛嶋 邦昭, 藤井 光一1979 年 43 巻 10 号 p. 890-895
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーIn an attempt to obtain WC-Co powders of which the particle size and carbon content were controlled, direct carburization of WO3 has been studied with special emphasis on the behaviour of carbon.
Mixtures of WO3, C and Co3O4 were heated in H2 at 750°C for 1 h for the reduction of oxides and then heated at a desired temperature above 800°C for 2 h for the carburization. Total and free carbon contents were determined at different stages of the heating process. The results are as follows.
(1) A remarkable decarburization occurred in the reduction process of oxides at 750°C, probably due to the two factors: one is H2O, which decreases the carbon content of the product by reacting with C in mixtures, and the other is Co, which acts on the formation of CH4 as a catalyst.
(2) The decarburization was depressed with increasing temperature above 800°C. At about 1000°C the cementation of the products was enhanced because Co acts on the reaction between CH4 and W as a catalyst.
Above results imply that in order to control the C-content in the products, the carbon content in the starting mixtures has to be determined referring to the decarburization and cementation reactions.抄録全体を表示PDF形式でダウンロード (489K) -
牛嶋 邦昭, 藤井 光一, 大塚 武夫1979 年 43 巻 10 号 p. 895-900
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーWC-(1∼6%)Co mixed powders obtained from the mixtures of WO3, C and Co3O4 were sintered. The mixed powders in which the Co content was adjusted by addition of Co powder were also sintered. The relation between the Co content of the starting powders and the WC grain size of the alloy was studied in comparison with usual alloys which was obtained from WC and Co powders. The following results are obtained.
(1) The starting powders containing more than 3% of Co could be sintered to the alloy having the full density and good strength without further addition of Co.
(2) The WC grain size of alloys depends on the Co content of the starting powder and the size was smaller with increasing Co content. Even in the alloys sintered at high temperature where grain growth of the carbide was observed, each WC grain size was uniform compared to usual WC-Co alloys sintered at the same temperature. The coarsening caused by the sintering decreased with increasing Co content of the starting powder.
(3) We found that the grain growth and hardness drop of alloys obtained from directly carburized powders were small even at high temperature sitering, compared to usual WC-Co alloy. Therefore, the temperature range suitable for the sintering is wider than that for usual WC-Co alloys.抄録全体を表示PDF形式でダウンロード (962K) -
会田 敏之, 本多 幸雄, 山本 恵彦, 川辺 潮1979 年 43 巻 10 号 p. 901-907
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーBaB6 powders have been prepared by the borothermic reaction from the starting materials of BaCO3 and B powders, and their thermionic emission characteristics have been measured. The results are as follows:
(1) The formation process of BaB6 consists of two steps; BaCO3+7B→BaB2O4+A∗+CO2↑, BaB2O4+A∗→BaB6+B2O2↑, where A∗ is an unknown phase which is considered to contain B as a main component.
(2) The BaB6 powders are fine crystals having the cubic shape with {100} habit planes. From X-ray and chemical analyses, the BaB6 powders were found to be a single phase.
(3) An attempt was made to synthesize various hexaborides by the borothermic reaction, and the temperature region for the preparation of hexaborides of the incongruent-melt type was found to be narrow. Atomic radii of metal elements can be employed as a measure of the stability of the hexaborides.
(4) After the activation of BaB6 powders at about 1000°C, high values of thermionic emission current density of 5 to 10 kA/m2 were obtained.
(5) For obtaining the high emission current density, it is essential to form a single phase BaB6 as shown by the X-ray diffraction measurement.
(6) The BaB6 powders prepared are 10 times higher in current density than other hexaborides. The BaB6 powders can be expected as a new cathode material due to the advantage of high electric conductivity.抄録全体を表示PDF形式でダウンロード (540K) -
佐藤 輝顕1979 年 43 巻 10 号 p. 908-917
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーRecently, high carbon steel tends to be widely used for machine and construction parts. The structure of these high carbon steels is pearlite when used as rolled or as forged. However, it is usually used as tough sorbite or sorbitic pearlite structures made by heat treatment. The welding of high carbon steel is less useful because of its high carbon equivalent, but is sometimes needed in actual cases.
In this paper, the relationship between the impact property and the structure of high carbon steel was first investigated using two materials. The first one is S58C whose structures are pearlite and sorbite. Heat treatment is a usual one as the high temperature heat treatment simulating heat affected zone. The second is the parts of welded rail joints, whose structures are also pearlite and sorbite. Secondly, the effect of structure on fatigue property was studied with respect to the above-mentioned sorbite structure of S58C and two structures of the welded rail joint.
The main results obtained are as follows. (1) In both properties, the sorbite structure made by heat treatment or welding is superior to the pearlite structure, and in each of the two structures the finer structure shows better properties. (2) In case of being changed into pearlite structure after heat treatment or welding, both properties of sorbite structure before heat treatment or welding are better than those of pearlite structure before heat treatment or welding. (3) In the case of heat treatments from 1373 K to 1573 K corresponding to the simulating high temperature heat affected zone, the grain size in the bond and its neighborhood of welding joints is made coarser, and consequently both properties are deteriorated. (4) Finally, the impact property increases as the grain size becomes finer and the hardness lowers. On the other hand, the fatigue property does not depend largely on the grain size but depend on the hardness.抄録全体を表示PDF形式でダウンロード (1066K) -
河原 正泰, 野田 剛弘, 森永 健次, 柳ヶ瀬 勉1979 年 43 巻 10 号 p. 918-922
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーThe measurements of electrical conductivity for CaO-SiO2-NiO-MgO and PbO-SiO2-NiO-MgO melts have been conducted to discuss the interaction of NiO and MgO contained in silicate melts. The measurements of infrared and far-infrared absorption spectra were carried out to discuss the dissociation of NiO in the silicate.
When NiO was replaced by MgO in CaO-SiO2 and PbO-SiO2 systems, the electrical conductivity tends to deviate from the additivity line to positive side. The absorption band of the molecular type (no dissociation to Ni2+ and O2−) of NiO observed in far-infrared region faded out with addition of MgO, and changed into that of dissociation type of NiO. It appears that the MgO promote the dissociation of NiO in silicate melts. The mechanism for interaction of NiO and MgO was discussed.抄録全体を表示PDF形式でダウンロード (376K) -
塚本 雄二, 立松 知重, 西川 俊次, 葉山 房夫1979 年 43 巻 10 号 p. 923-929
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーIt has been found that an important variable that affects the abrasive wear is the size of the abrasive grains. Previous workers have shown that there exsists a minimum abrasive particle size which allows maximum abrasive wear. This critical size effect was studied in this paper.
Experments were performed with various brasses sliding against abrasive clothes, and using conical diamond indenters scratching tests were carried out to simulate an abrasive grain cutting a groove.
The critical size effect is explained by two terms of the true contact area and the material removal ratio. First the true contact area is decreased with the small grit size. Secondly the number of contact points increase with finer abrasive clothes. Therefore the load carried by an abrasive grain is diminished and the penetration depth of an abrasive particle becomes shallower. In this situation the transition from cutting to ploughing occurs, and the material removal ratio is diminished. Consequently, as the abrasive size is increased, there is an initial increase in wear until a certain abrasive size is reached.
As an increase of the applied load leads mainly to an increase of the number of contact points and an abrasive grain acts in the same manner, the value of the critical abrasive grain size is not changed by the applied load.抄録全体を表示PDF形式でダウンロード (685K) -
江島 辰彦, 横尾 俊信, 斎藤 元治, 加藤 吉明1979 年 43 巻 10 号 p. 929-938
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーViscosity coefficients of the molten ZnCl2-MCl (M=Li, Na, K, Cs) binary systems have been measured in the composition range of 50∼100 mol%MCl at temperatures of 610 to 1240 K. In order to calculate the viscosity coefficient with the measured logarithmic decrement and oscillating period by the absolute method, Roscoe’s equation derived for a cylinder vessel having a free liquid surface has been used in the present work. The results obtained are summarized as follows:
(1) The composition dependence of the viscosity coefficients and activation energies for viscous flow are determined for the whole range of composition on the basis of the data obtained in the present and previous works. Both the viscosity coefficient and the activation energy decrease with increasing MCl content. However, the ZnCl2-KCl and -CsCl systems exhibit maxima near the stoichiometric composition of M2ZnCl4(66 mol%MCl). This trend clearly indicates that the donor effects of Cl− ion of KCl and CsCl for the formation of ZnCl42− are stronger than those of LiCl and NaCl.
(2) There is a linear relationship between the fluidity and the molar volume in the composition range of more than 50 mol%MCl. But, this relationship fails on the ZnCl2-rich side especially in the vicinity of the melting point. Deviations from the linearity increase as the content of ZnCl2 increases. These facts suggest a remarkable structural change in the liquid of ZnCl2-rich side.
(3) Based on the results obtained, chemical species in these melts are estimated.抄録全体を表示PDF形式でダウンロード (776K) -
宮城 政和, 佐藤 幸弘, 水野 利昭, 沢田 重政1979 年 43 巻 10 号 p. 939-947
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーTitanium surfaces nitrided in a N2 or NH3 stream and ion-nitrided in an atmosphere of N2 or a N2-H2 gas mixture were examined by ESCA. The following results were obtained. (1) The ESCA spectrum of Ti2p3⁄2 obtained from nitrided titanium was able to decovoluted into three peaks. A peak at a B.E. of 457.3 eV was interpreted as originating from TiNx (x>1), which was a hyperstoichiometric mononitride. The other peaks at 458.8 and 455.4 eV was identified as TiO2 and TiN, respectively. (2) As the N1s spectrum excited by Mg-Kα radiation exhibited two peaks, the existence of two kinds of titanium nitrides, that is, TiN and TiNx, is thought to be reasonable; the main peak at 397.2 eV seemed to be due to TiN and the minor one at 395.8 eV due to TiNx. (3) The dependence of ESCA peak intensities on the take-off angle of photo-electrons suggested that the nitrided titanium surface consisted of three layers; a topmost layer of TiO2, a midle layer of TiNx and an inner layer of TiN. (4) TiNx was readily formed when hydrogen was contained in the nitriding atmosphere. (5) The titanium nitrides were formed temperatures above 823 K by N2 gas-nitriding, and above 623 K by ion-nitriding. The formation of titanium nitride at low temperature by ion-nitriding seemed to suggest the essential difference in the nitriding process between gas and ion-nitriding.抄録全体を表示PDF形式でダウンロード (701K) -
千葉 実1979 年 43 巻 10 号 p. 947-951
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーOxygen in zinc dust was determined by means of non-destructive 14 MeV neutron activation analysis. Oxygen was determined by counting of gamma-rays radiated from 16N produced by the 16O(n, p) reaction.
Interferences caused by 63Zn, 66Cu and 68Cu which are the main radio active nuclides produced from matrix zinc by 14 MeV neutron irradiation were eliminated by counting the energy range of 4.5∼8 MeV of gamma-rays of 16N. A small interference caused by the random sum counts of 63Zn was removed by counting 30 s twice after 1.5 and 60 s of decay duration from the end of 14 MeV neutron irradiation and subtracting the second counts from the first counts as the background.
A calibration curve with good linearity and analytical results with good reproducibility were obtained by adopting the external method which consists of the simultaneous irradiation of a standard or analytical sample and an external standard, and calculation of count ratio of 16N produced in the standard or the analytical sample and the external standard, respectively.
The irradiation of samples with 14 MeV neutron flux was carried out by the constant time method. A series of standard samples were prepared by adding a known amount of oxygen in a zinc dust.
As the result, oxygen contents of 0.42∼3.24% with coefficient of variations of repetition of 4.03∼7.15% were obtained for two trial-produced zinc dusts (gas atomizing and stamping methods) and four commercial zinc dusts.
The duration needed for the 14 MeV neutron irradiation and counting was about 2.5 m for a sample.
The presence of stearic acid used as a lubricant was not effective to protect zinc dust from oxidation.抄録全体を表示PDF形式でダウンロード (383K) -
岡崎 秀雄, 柴田 斉治1979 年 43 巻 10 号 p. 952-957
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーAs considerable attention has been given to the ternary alloys of Ag-Ge-S in the glassy state because of the highly ionic conduction of silver ions, the atomic structure of these materials has been investigated by X-ray diffraction. Two series of specimens have been examined: One is AgxGe2S3 (x=0∼2.1) alloys in which a given amount silver atoms is dissolved. The other is AgxGe1−xS (x=0.33∼0.7) alloys in which a portion of germanium atoms is replaced by silver atoms. The intensity measurements of X-ray diffraction have been carried out by the step scanning method with MoKα radiation in the range of 5° to 150°. The interference function was derived from the analysis of data and the pair distribution function gE(r) has also been obtained by the Fourier transformation. The following results have been obtained:
(1) In AgxGe2S3, the nearest neighbour distance R1 increases with increasing x. A similar behaviour is seen in GeXS, where X varies from 2.0 to 1.0. In AgxGe1−xS, on the other hand, R1 does not change with x.
(2) In both series of the specimens, the height of first peaks decreases with increasing x, while the peak width increases.
(3) In AgxGe2S3, the coordination number obtained from the first peak of gE(r) increases with increasing x, but in AgxGe1−xS the coordination number does not change with x.
A theoretical pair distribution function gC(r) has been estimated on the assumption that the atomic position of GeS and GeS2 is spatially fluctuated by a Gaussian probability. The results fairly agree with the experimental ones, which implies that the basic structures of both series resemble to those of GeS and GeS2. Since the peak width of gE(r) increases with the amount of silver atoms, it might be suggested that a part of siler atoms occupies the “interstitial site” and consequently these “interstitial ions” contribute to the highly ionic conduction.抄録全体を表示PDF形式でダウンロード (438K) -
三沢 俊平, 菅原 英夫, 原田 正1979 年 43 巻 10 号 p. 958-966
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーA study has been made of corrosion fatigue crack growth for Inconel 600 solution-annealed at 1100°C for 0.5 h in 85°C 50%NaOH solution with a frequency of 1.1 cycle per minute. The effect of potential on the corrosion fatigue crack growth rate (da⁄dN) as a function of ΔK was examined and the fracture surfaces were observed. The results obtained are as follows:
(1) The crack growth rate and the cracking mode were affected by the applied potentials in the anodic polarization curve. The value of da⁄dN was arranged in the following order of the observed potentials: secondary passive region>corrosion potential>primary active region>primary passive region.
(2) Intergranular cracking took place at a secondary passive potential (−0.04 V vs SCE) which gave a maximum crack growth rate. Transgranular cracking with fatigue striations occurred at the other potentials.
(3) The variation in current with the alternating loading was observed at the potentials where transgranular cracking occurred, whereas no appreciable correlation between current and cyclic loading was shown at a potential of −0.04 V where the intergranular mode cracking occurred.
(4) It is pointed out to be helpful in studying the influence of applied potential on the acceleated rate of cracking at the crack tip by the “crack-tip opening displacement” estimated from the stress intensity, as the major mechanical condition.抄録全体を表示PDF形式でダウンロード (1371K) -
鈴木 建次, 三谷 裕康, 中西 典彦1979 年 43 巻 10 号 p. 966-971
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーEffects of chemical compositions, porosities and cooling rates on the maximum internal friction were examined for sintered Cu-Al-Ni ternary alloys which were heat-treated after sintering, and the results obtained are as follows.
(1) The maximum value of Q−1max in sintered Cu-Al-8 wt%Ni alloys with different Al contents was obtained at 14 wt%Al.
(2) The value of Q−1max in sintered Cu-14 wt%Al-Ni alloys increased with increasing Ni content and showed a maximum value at 8 wt%Ni, where the value of Q−1max is propotional to the amount of γ′ martensite.
(3) The value of Q−1max in sintered Cu-14 wt%Al-8 wt%Ni alloys increased slightly with increasing porosity. On the other hand, the Q−1max was kept constant at the rates higher than 300°C/min after showing a linear increase with increasing cooling rate up to about 300°C/min. These results indicated that Q−1max depended on the amount of γ′ martensite rather than that of porosities, where γ′ single phase martensite could be obtained from the sintered Cu-14 wt%Al-8 wt%Ni cooled at the rates higher than 300°C/min.抄録全体を表示PDF形式でダウンロード (722K) -
松島 成夫, 野沢 光治1979 年 43 巻 10 号 p. 972-977
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーA diffusion welding model based on weakness of welded parts and voids is proposed. From the weakness and Griffith’s criterion for the plastic material, apparent fracture strength \barσB is derived as a function of welded area A and pitch 2\barc (of the welded part or void) for the diffusion welding metal:
(This article is not displayable. Please see full text pdf.)
where W is the fracture load, A0 the apparent area (area of the welding surface), σB the ultimate strength, rp the plastic surface energy for the crack proceeding, E Young’s modulus and ν Poisson’s ratio.
The validity of the above expression is confirmed by the experiment of fracture strength of diffusion welding copper.抄録全体を表示PDF形式でダウンロード (682K) -
植田 幸富, 小野 勝敏, 森山 徐一郎1979 年 43 巻 10 号 p. 978-983
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーNiobium and niobium alloys have received considerable attention as engineering materials for use in aerospace and gas turbine applications. The carbothermic reduction-electron beam melting combination method has made possible to prepare the pure niobium metal. Similar to the carbothermic reduction of niobium in vacuum, simultaneous reduction of niobium alloys from the mixtures of constituent metal oxides is expected to be possible. In this process alloying would proceed even in the first reduction stage and be completed at the final refining period. Subsequent melting in an electron beam furnace lowers the carbon and oxygen contents to a commercial grade and consolidates the sintered alloys into ingot. A complete homogenization and excellent control of the residual interstitial element contents in the alloys have to be assured for this manufacturing process to be feasible.
The mixtures of Nb2O5 and MoO2 were reduced withcarbon in vacuum at about 2200 K, and the Nb-Mo alloys thus obtained were melted in an electron beam furnace. The evaporation deoxidation as suboxides of niobium plays an important role in this process. The purity and homogeneity of the alloys thus prepared has been a ssured to be a sufficient degree.抄録全体を表示PDF形式でダウンロード (542K) -
佐藤 譲, 館山 政美, 江島 辰彦1979 年 43 巻 10 号 p. 984-991
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーElectrical conductivity of LiCl-NaCl-AlCl3 ternary melts has been measured over the composition range of less than 50 mol% AlCl3 and the temperature range of 800∼1200 K by using the conductivity cell made of quartz.
\ oindentThe results obtained are summarized as follows:
The conductivity of the ternary melt decreases with an increase in AlCl3 content, and in the composition range of less than about 40 mol% AlCl3, the conductivity increases with increasing ratio of the LiCl to NaCl content. The conductivity was expressed as a function of temperature and composition.
By regarding the ternary melt as a reciprocal melt of (Li+, Na+||Cl−, AlCl4−), the equivalent conductivity and the activation energy for conductance were calculated. The equivalent conductivity shows a minimum value at the cationic fraction of Na+ from 0.6 to 0.9 and the anionic fraction of AlCl4− from 0.1 to 0.3. Also the equivalent conductivity showsa slight negative deviation from additivity for the cationic fraction, and a large deviation for the anionic fraction. The activation energy for conductance remains nearly constant for the cationic fraction, but exhibits a remarkable variation for the anionic fraction and shows a maximum value at about 0.2 of the anionic fraction of AlCl4−.
For industrial purposes, the LiCl-NaCl-AlCl3 ternary melt may be used for the electrolytic bath of aluminum due to its high conductivity. However, it is necessary to keep the concentration of AlCl3 in the melt constant because the conductivity varies greatly with AlCl3 content, particularly in the region of low AlCl3 content.抄録全体を表示PDF形式でダウンロード (643K) -
原 信義, 杉本 克久1979 年 43 巻 10 号 p. 992-999
発行日: 1979年
公開日: 2008/04/04
ジャーナル フリーModulated reflection spectra of Pt electrodes with two-layer oxide films of γ-Fe2O3 and Cr2O3, which were coated by the CVD technique, have been measured in 1.0 mol/l-Na2SO4 (pH 6.0) in order to evaluate the application of modulation spectroscopy to the analysis of surface films which are of non-homogeneous composition in thickness.
It was found that the spectra of the electrodes were dependent on the composition and thickness of the outermost layers of the surface films which, when exceeding a specific thickness, mask the effects of the inner layers on the spectra. For example, the values of specific thickness were 0.7 and 0.5 nm for Cr2O3/γ-Fe2O3/Pt and γ-Fe2O3/Cr2O3/Pt electrodes, respectively.
From Mott-Schottky analysis of the capacitance vs potential relationships for Pt electrodes covered with single layer films of γ-Fe2O3 or Cr2O3, it was concluded that thin space-charge regions of about 0.35 and 0.5 nm thick exist in γ-Fe2O3 and Cr2O3 films, respectively. Since the values of specific thickness for the outermost layers of the two-layer oxide films are very close to the thickness of space-charge regions, it is thought that the modulated reflection spectra of metals covered by such oxide films are determined by the chemical composition and energy band structures of space-charge regions.抄録全体を表示PDF形式でダウンロード (682K)
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