巻号一覧
48 巻, 3 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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下斗米 道夫, 藤沢 英幸, 堂山 昌男1984 年 48 巻 3 号 p. 233-237
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーWe have designed an SmFe2-based pseudo-binary Laves phase compound in which the spin-reorientation arises around room temperature, taking into account the effects of the crystalline electric field and the atomic size of the constituent elements. Theoretical calculation of the easy-axis diagrams based on the interaction of 4f electrons with the crystalline electric field has predicted that a half substitution of Pr atoms for Sm atoms in SmFe2 raises the spin-reorientation temperature from 175 K to room temperature. Such an alloying effect is not expected for other light rare earth elements. We have synthesized a compound with the optimum composition, i.e. Pr0.5Sm0.5Fe2, using the technique of high pressure. Its spin-reorientation temperature, as determined by the Mössbauer spectroscopy, is near room temperature in good agreement with the theoretical design. This compound could be applied as a magnetostrictive and magnetoelastic material. We have found that the magnetic anisotropy of PrxSm1−xFe2 is described by the single-ion crystalline electric field model in the whole range of the composition and that the lattice parameter deviates distinctly from the Vegard’ law like some of pseudo-binary intermediate valence compounds.抄録全体を表示PDF形式でダウンロード (730K) -
米澤 利夫, 鬼村 吉郎, 坂元 成夫, 笹栗 信也, 中田 英則, 薄田 寛1984 年 48 巻 3 号 p. 238-247
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーIn order to improve the resistance of the Alloy X-750 in high temperature and high purity water, the authors investigated the influence of heat treatment condition on the stress corrosion cracking resistance of the alloy.
This paper describes results of the stress corrosion cracking test and some discussion on the mechanism of the stress corrosion cracking of Alloy X-750 in deaerated high temperature water.
\ oindentThe following results were obtained.
(1) The stress corrosion cracking resistance of Alloy X-750 in deaerated high temperature water remarkably depended upon the heat treatment condition. The materials solution heat treated and aged within temperature ranges from 1065 to 1100°C and from 704 to 732°C, respectively, have a good resistance to the stress corrosion cracking in deaerated high temperature water. Especially, water cooling after the solution heat treatment gives an excellent resistance to the stress corrosion cracking in deaerated high temperature water.
(2) Any correlations were not observed between the stress corrosion cracking susceptibility of Alloy X-750 in deaerated high temperature water and grain boundary chromium depleted zones, precipitate free zones and the grain boundary segregation of impurity elements and so on. It appears that there are good correlations between the stress corrosion cracking resistance of the alloy in the environment and the kinds, morphology and coherency of precipitates along the grain boundaries.抄録全体を表示PDF形式でダウンロード (1635K) -
大平 貴規, 岸 輝雄, 宮下 博仁, 香川 豊, 中田 栄一1984 年 48 巻 3 号 p. 248-255
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーAcoustic emission source characterization was applied to the study of fiber fracture processes in Cu-W composites. The source function was formulated as the time history of the product of cross section area, ΔA, distance between fracture surfaces, φ(t) and elastic modulus of tungsten fiber, from which φ(t) was determined since ΔA and elastic modulus could be regarded as constants. Using this method, it was shown that φ(t) reached its final value φ0 of 29∼61 μm within 1.1∼2.1 μs after fiber fracture, and φ0 agreed well with that from direct observation. Furthermore the initial velocity of fractured fiber φ(0)/2 was remarkably consistent with that calculated from the one-dimensional elastic fracture model of tungsten fiber.抄録全体を表示PDF形式でダウンロード (1246K) -
武田 武信, 菊地 新一, 那須 康雄, 辛島 誠一1984 年 48 巻 3 号 p. 255-261
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe present investigation was undertaken to examine the relation between fatigue crack propagation characteristics and microscopic fracture mechanisms at low crack propagation rates in a mild steel. In particular fractographic aspects on the fracture surfaces were examined and discussed in connection with the knee of the crack propagation rate-stress intensity factor range curve (log(dl⁄dN)−log(ΔK) curve) and with the transition from Stage 2a to Stage 2b in crack propagation. Fatigue tests were performed under pulsating ex-plane bending using notched specimens with a small circular hole. The fracture surfaces of specimens were examined by transmission and scanning electron microscopies. The resuls are summarized as follows:
(1) The value of crack propagetion rate, dl⁄dN, changes in a pulsating manner at an early stage of crack propagation in maximum stress-constant tests. In this range three types of microscopic features, that is, intergranular facets, a striation-like pattern and a shear mode pattern superimposed by the striation-like pattern are observed.
(2) In the range of dl⁄dN above the knee of the log(dl⁄dN)−log(ΔK) curve, Paris’ power law is valid. In this range the plastic zone size developed at the crack tip increases with crack propagation, and the shear mode pattern disappears.
(3) At the transiton point from Stage 2a to Stage 2b, the area fraction of intergranular facets takes a maximum value.
(4) The striation spacing is larger than the value of dl⁄dN and takes a constant value at Stage 2a, whereas it is proportional to dl⁄dN at Stage 2b.
(5) In the range of dl⁄dN below the knee, the area of the shear mode pattern becomes larger, as dl⁄dN becomes lower.抄録全体を表示PDF形式でダウンロード (1558K) -
李 基淳, 諸住 正太郎1984 年 48 巻 3 号 p. 262-266
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe effect of substitutional alloying elements, such as niobium, titanium, vanadium and zirconium, on the nil ductility transition temperature of molybdenum was studied by a three point bend test. All the specimens were prepared by arc-melting with 0.2 mass% of scandium as a deoxidizer, then rolled and stress-relieved by annealing.
With increasing alloy content, the yield stress was increased, and the transition temperature was shifted to the higher temperature side, but the cleavage fracture stress was little affected. Since the increase in yield stress was related to the atomic size effect of the elements, it was concluded that the rise of the transition temperature was attributed to the solid-solution hardening of the elements.抄録全体を表示PDF形式でダウンロード (1722K) -
岩井 正雄, 真嶋 宏, 粟倉 泰弘1984 年 48 巻 3 号 p. 267-272
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe oxidation of As(III) with oxygen in alkaline solutions was investigated from a kinetic point of view. The oxidation rates of As(III) obey the equation,
(This article is not displayable. Please see full text pdf.)
\ oindentin aqueous NaOH and KOH solutions. The principal rate limiting step for this oxidation reaction appears to be a chemical reaction process. The evidences which support this analysis include an apparent activation energy of 73.2 kJ·mol−1 and an independence of reaction rates of the agitation speed. The oxidation rates of As(III) increased in various alkaline solutions according to the sequence of KOH<NaOH<LiOH. This sequence coincides with the order of the amount of free water in the solutions. It was also observed that the accumulation of As(V) tends to suppress the reaction slightly.抄録全体を表示PDF形式でダウンロード (821K) -
岩井 正雄, 真嶋 宏, 栗倉 泰弘1984 年 48 巻 3 号 p. 272-277
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe kinetics of the oxidation of As(III) with oxygen in alkaline solutions in the presence of Cu(II) was studied. The oxidation reaction of As(III) proceeds via two different paths; one is independent of pO2, while the other is dependent on pO2. The former path is influenced by the concentration of alkali, showing the suppressed tendency with the increase in alkali concentration. On the other hand, the latter path is independent of the concentration of alkali. The dependences of the two paths on the concentration of Cu(II) appeared to be different from each other.
The experimental rate equation was found to be
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\ oindentThe apparent activation energy is 105.3 kJ·mol−1 for the former path and 21.3 kJ·mol−1 for the latter path. The reaction rate is affected by presence of alkali in the solution, exhibiting an accelerating tendency according to the sequence of LiOH<NaOH<KOH.抄録全体を表示PDF形式でダウンロード (750K) -
竹森 信, 本間 禎一1984 年 48 巻 3 号 p. 278-284
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーSurface Segregation of sulfur is often observed, when metals and alloys are annealed in vacuum. Though this phenomenon has been thought to be pretty reproducible, it recently has come to be realized that the reproducibility is not quite well and many factors are important to control this phenomenon. The fact is that, when the surface is exposed to oxygen at room temperature, the sulfur segregation is often enhanced during subsequent vacuum annealing. In order to know where the sulfur comes from during the enhanced segregation annealing, and to know about the mechanism of this enhancement, a sulfur-doped nickel polycrystalline specimen and a sulfur-containing Fe-18Cr polycrystalline alloy were used and examined by an Auger analyzer. After repeating a series of vacuum annealing and sputtering, or combined oxidation and annealing treatment, little sulfur segregated from the bulk for both specimen surfaces. Exposure to oxygen or air at room temperature enhanced the segregation in each case. Auger analyses before and after annealing, and residual gas analyses during annealing showed that the enhanced sulfur segregation originated form the bulk, not from gas atmospheres. The Fe-18Cr specimen showed a remarkable recovery of segregation, accompanied by a strange phenomenon, perhaps exoelectron emission. It can be suggested that not only the topmost-surface but the bulk of some depth might be affected by oxygen adsorption at room temperature.抄録全体を表示PDF形式でダウンロード (1085K) -
下尾 聰夫, 安藤 繁, 木村 弘1984 年 48 巻 3 号 p. 285-292
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe rate of MnO reduction from CaO-Al2O3 slag melted in a graphite crucible as a reductant has been determined. At temperatures between 1823 and 1973 K and under Ar atmosphere, the mass loss was continuously measured by means of thermo-balance.
The mass balance indicated that most of the produced molten manganese was evaporated for slag initially containing MnO less than 8 mass%, and that the rate of MnO reduction was nearly equal to that of Mn evaporation. The reduction rate remained constant in the range of reduction degree from 10 to 60%. It was found that the reduction rate was markedly dependent on the wetting of slag on the graphite crucible wall. In the range of 1.06<CaO/Al2O3<1.26, the reaction was approximately of the first order in regard to the activity of MnO, and the activation energy for reduction was 397 kJ/mol. It was supposed that the reaction proceeded primarily by the direct reduction and the rate was controlled by chemical processes at the slag-graphite interface.抄録全体を表示PDF形式でダウンロード (1158K) -
伊藤 聰, 阿座上 竹四1984 年 48 巻 3 号 p. 293-301
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe E.M.F. measurements of the following solid oxide galvanic cells have been carried out to determine the oxygen partial pressure of air, the standard free energy of formation of FexO, Bi2O3 and Sb2O3 and the thermodynamic quantities of liquid Bi-Sb alloys.
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\ oindentThe oxygen partial pressure of air was ascertained to be PO2/kPa=21.18±0.10. The standard free energy of formation of FexO, Bi2O3 and Sb2O3 were determined as follows:
(This article is not displayable. Please see full text pdf.)
\ oindentThe activities of antimony and bismuth in Bi-Sb alloys were calculated at 973, 1073 and 1173 K. The activity of antimony showed slightly positive and negative deviations from the Raoult’s law, depending on the concentration of antimony. The activity of bismuth showed a slight positive deviation from the Raoult’s law over the whole concentration range. The activity coefficients of bismuth and antimony at infinite dilution were also calculated.抄録全体を表示PDF形式でダウンロード (1317K) -
大森 正信, 伊藤 操, 吉田 総仁, 井上 美智正1984 年 48 巻 3 号 p. 302-307
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe present paper describes a testing apparatus in which some deformations such as tension and blanking can be given to metals at ambient temperature under hydrostatic pressure up to 700 MPa and with deformation speed up to 1 m·s−1.
Using this apparatus, tensile tests of a high purity polycrystalline zinc were carried out in a wide range of deformation speed. The finding of increase in the brittle-to-ductile transition pressure with increasing strain rate is discussed on the basis of rate dependence of fracture stress.抄録全体を表示PDF形式でダウンロード (1004K) -
駒井 謙治郎, 箕島 弘二, 藤戸 敏弘1984 年 48 巻 3 号 p. 307-313
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーStress corrosion Cracking (SCC) initiation behavior was examined on a high-strength low alloy steel sensitive to hydrogen embrittlement (HE) type SCC under a sustained load with vibratory stresses of small amplitude superimposed in an open circuit and cathodically charged conditions in 3.5%NaCl solution. In an open circuit condition, time to crack initiation under a sustained load with superimposed vibratory stress range greater than 74 MPa is shorter than that of static SCC under a sustained load, resulting in lower 600 ks strength than that of static SCC σSCC. At a stress range Δσ smaller than 74 MPa, however, 600 ks dynamic SCC strength hardly decreases from σSCC. In case of σmax>σSCC SCC cracks are always initiated at corrosion pits formed on specimen surfaces irrespective of superimposed vibratory stress range. On the other hand, at σmax<σSCC and Δσ>74 MPa, the superimposed vibratory stresses promote stress assisted crack-like dissolution preceded by a corrosion pit. Dynamic SCC crack is initiated at the bottom of crack-like portion, thereby reducing the dynamic SCC strength. K*ISCC calculated from the sizes of corrosion pits and crack-like portion is roughly equivalent to KISCC obtained from a long sharp one.
When a cathodic potential is applied to specimens, corrosion pits or stress assisted crack-like dissolution preceded by corrosion pits, are no more generated, and no dependence of superimposed vibratory stresses of small amplitude on 600 ks SCC strength is shown. In this situation hydrogen occulusion is much more enhanced than that in an open circuit, and SCC crack is initiated at the interior of the specimen where hydrostatic pressure reaches the maximum.抄録全体を表示PDF形式でダウンロード (2450K) -
比内 正勝, 増本 量, 沢谷 昭八1984 年 48 巻 3 号 p. 314-319
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe internal friction Q−1, the magnetic hysteresis loop and the mechanical properties were investigated for three Ni-Co-Nb alloy series containing 25, 45 and 65%Co, respectively. Measurements of the Q−1 and the rigidity modulus G were carried out by the inverted torsion pendulum method. The coercive force Hc was measured using an automatic recording fluxmeter, and the tensile test was performed using an Instron-type machine.
In both states of furnace-cooling and water-quenching, the maximum internal friction, Qmax−1, for the maximum shear strain-amplitude became the highest at 3%Nb for the Ni-25%Co-Nb alloy series and at 5%Nb for the Ni-45%Co-Nb alloy series. For the Ni-65%Co-Nb alloy series, the Qmax−1 became the highest at 1%Nb upon furnace-cooling or at 5%Nb upon water-quenching.
The Qmax−1 value of the alloys having the reasonably small Hc was fairly high, while the Qmax−1 of the alloys having the large Hc was very low, because the compound Co2Nb or Co3Nb precipitated in the α phase matrix. Furthermore, the larger the ΔG effect, the higher the Q−1 became.
The tensile strength and the yield strength of the present three alloy series increased with increase in Nb content, and the elongation of these alloys was generally large.抄録全体を表示PDF形式でダウンロード (745K) -
増本 量, 比内 正勝, 沢谷 昭八1984 年 48 巻 3 号 p. 319-323
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe logarithmic decrement δ, the rigidity modulus G and the tensile strength σt were studied on Al-Si alloys containing 0-15%Si after heat-treating or subsequent cold-working. Measurements of δ and G were carried out by the inverted torsion pendulum method at a frequency of 1 Hz, and the σt was measured using an Instron-type testing machine.
The water-quenched alloys show the lower δ than that of the furnace-cooled alloys. The δ values of heat-treated alloys are generally low, and increase with Si content. The δ becomes fairly higher by cold-working after heat-treatments.
The G and σt values of the heat-treated alloys increase with Si content. These alloys show larger G when furnace-cooled than that when water-quenched, and show larger σt when water-quenched. By cold-working, the G becomes smaller and the σt becomes larger.抄録全体を表示PDF形式でダウンロード (562K) -
比内 正勝, 増本 量, 沢谷 昭八1984 年 48 巻 3 号 p. 323-326
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe influence of cold-working on the damping capacity and the mechanical properties was investigated for Al-0.2∼6 mass%Fe alloys. The logarithmic decrement δ and the rigidity modulus G were measured by the inverted torsion pendulum method, and the tensile strength σt by an Instron-type machine.
In the states of furnace-cooling and water-quenching, the δ has a fairly low value, 3-6×10−3, increases gradually with the increase in Fe content up to 2% and then becomes nearly constant.
By cold-working after the heat treatments, the δ becomes considerably higher with increasing reduction rate of area RA, and that of the alloys cold-worked by 95% RA has a large value, about 40×10−3. The δ of the alloys cold-worked after furnace-cooling is higher than that after water-quenching. The increase in δ by cold-working should be due to dislocations. It appears that the compound Al3Fe (θ phase) acts on the motion of dislocations.
The G in the heat-treated alloys increases gradually up to 6%Fe, while the σt increases up to 4%Fe and then decreases gradually. By cold-working, the G decreases and σt increases.抄録全体を表示PDF形式でダウンロード (456K) -
大貫 仁, 諏訪 正輝1984 年 48 巻 3 号 p. 327-332
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーWhen a n+-type surface of a diode is bonded to an electrode using aluminum solder, a thin p-type silicon layer, i.e. a regrowth layer is formed on the n+-type silicon after bonding. Because of the layer formation, a considerably high forward voltage drop (FVD) is observed in the regrowth layer.
In the present investigation, molybdenum and tungsten were used for electrode. The phosphorous concentration in the diodes used were 2×1020 cm−3, 4×1020 cm−3 and 1.6×1021 cm−3. Effects of both electrode material and P concentration in diodes on FVD have been investigated. In the case of diodes with high P concentration (1.6×1021 cm−3), FVD was lowered by the use of molybdenum electrode in comparison with the case of tungsten electrode. However, in the case of low P concentration (2×1020 cm−3, 4×1020 cm−3) diodes, the reverse was true. These results are explained by the fact that in the case of molybdenum electrode, the dissolution of n+-type silicon into molten aluminum was increased and the thickness of regrowth layer was reduced in comparison with the case of tungsten electrode.抄録全体を表示PDF形式でダウンロード (1163K) -
大貫 仁, 諏訪 正輝1984 年 48 巻 3 号 p. 333-338
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーWhen a n+-type surface of a diode is bonded to a tungsten or molybdenum electrode using aluminum solder, a thin p-type regrowth layer is formed on the n+-type silicon after bonding. This layer formation generates a considerable forward voltage drop (FVD) in the regrowth layer.
In order to clarify the role of phosphorous in brazing between n+-type silicon and aluminum, effects of P concentration on the thickness and the electrical property of regrowth layer have been investigated.
The P concentrations in n+-type silicon of diodes were 1×1020 cm−3, 4×1020 cm−3 and 2×1021 cm−3. Brazing atmospheres used were N2, air and vacuum. In the case of brazing in N2 atmosphere, the thickness of regrowth layer is increased with increasing P concentration in n+-type silicon. Difference in the thickness and the morphology of regrowth layer between n+-type silicon with high P concentration and that with low P concentration, becomes more remarkable by brazing in air. On the other hand, in the case of brazing in vacuum, the thickness of regrowth layer is nearly the same independent of P concentration. These results indicate that cleaning action in the interface between molten aluminum and n+-type silicon is greatly promoted by the presence of P. It is also found that in n+-type silicon with high P concentration, the junction formed between regrowth layer and n+-type silicon is more imperfect than that of n+-type silicon with low P concentration.抄録全体を表示PDF形式でダウンロード (1283K)
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