巻号一覧
56 巻, 6 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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連川 貞弘, 田中 智昭, 吉永 日出男1992 年 56 巻 6 号 p. 609-618
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe fracture strength in molybdenum depends markedly on the grain bounday character. In order to clarify the relationship between the strength and the grain boundary structure, bicrystals with ⟨110⟩ symmetric tilt boundaries were prepared and observed by means of transmission electron microscopy. The observations were conducted using the bicrystals with near Σ1 and Σ3 boundaries, which are higher in fracture strength, and with boundaries of misorientation angle around 30°, which are lower in fracture strength. The results obtained are as follows.
(1) Σ1 low angle and near Σ3 coincidence boundaries have a good coherency. The grain-bounday dislocations are observed and they can be described by a boundary dislocation model. (2) The boundaries of misorientation angle around 30° are poor in coherency comparing with Σ1 and Σ3 boundaries. However, the grain boundary structure can also be described by the grain-boundary dislocation model. (3) It is considered that the grain boundary structure in molybdenum with a high covalency in bonding is not greatly different from that in normal metals.抄録全体を表示PDF形式でダウンロード (4167K) -
渡辺 英雄, 室賀 健夫, 吉田 直亮1992 年 56 巻 6 号 p. 619-625
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe effect of phosphorus on void swelling in austenitic stainless steels under fast neutron irradiation has been investigated. Three types of model alloys (Fe-16Cr-17Ni, Fe-16Cr-17Ni-0.024P, Fe-16Cr-17Ni-0.1P) were irradiated to 40 dpa in the Fast Flux Test Facility (FFTF)/Materials Open Test Assembly (MOTA). The irradiation temperatures were 679, 793 and 873 K.
Addition of phosphorus showed remarkable suppression in void swelling at all temperatures. At the higher temperatures (793 and 873 K), radiation enhanced formation of Fe2P-Type phosphides were observed. These phosphides are expected to act as strong defect sinks, which resulted in remarkable swelling suppression at these temeratures. On the other hand, at the lower temperature (679 K), the swelling suppression seemed to be related with the reduction of vacancy mobility by phosphorus, which was shown in the previous HVEM studies.抄録全体を表示PDF形式でダウンロード (1589K) -
和才 京子, 加納 誠, 向井 楠宏1992 年 56 巻 6 号 p. 626-635
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーAn associated solution model was developed for describing the concentration dependence of the specific heat capacity of a liquid alloy at constant pressure, Ctp.
Using an ideal associated solution model (IASM), the following equation is derived.
(This article is not displayable. Please see full text pdf.)
where the subscript i is a number given to each species in the A-B binary liquid alloy consecutively, and all the species are expressed by the molecular formula, ApiBqi: Ap1Bq1(i=1: p1=1, q1=0) and Ap2Bq2(i=2: p2=0, q2=1) show monomers, A1 and B1, respectively, and ApiBqi(i≥3: pi, qi=1,2,3—) shows associated compounds; xi, Cip and ΔHi° denote the molar fraction of the i’th speices, the molar specific heat capacity at constant pressure of the i’th speices, and the standard enthalpy of formation of the associated compound, respectively. The first term on the right-hand side in Eq.(1) indicates the additivity of molar specific heat capacity (Neumann-Kopp’s rule). On the other hand, the second term is caused by the heat of dissociation of associated compounds, since ∂xi\ominus⁄∂T is a function of ∂xi⁄∂T. ∂xi⁄∂T can be calculated by IASM. Then, ΔCtp(=Ctp−XAC1p−XBC2p) was calculated for the alloy system with one associated compound, AlBm (AB, AB2, or A2B3 (i=3)), assuming the C3p=l·C1p+m·C2p, where XA and XB and the mole fraction of A and B in the bulk alloy. The calculated results of ΔCtp are shown graphically as a function of XB, and the effects of ΔH3° and K3 on ΔCtp are discussed, where K3 is the equilibrium constant of formation reaction of AlBm.
The observed specific heat capacity of the Cd-Sb System were analysed assuming the associated compounds CdSb and Cd4Sb3. The calculated specific heat capacities agree well with the observed values.抄録全体を表示PDF形式でダウンロード (1348K) -
伊 昌伸, 榎本 英彦, 小見 崇1992 年 56 巻 6 号 p. 636-640
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーStructure and Hardness of a recently found Fe-1 mass%C alloy film electrodeposited from an Iron(II) sulfate electrolyte containing small amounts of citric acid and L-ascorbic acid were studied by X-ray diffraction, electron-microscopy, X-ray photoelectron spectroscopy and measurement of micro-Vickers hardness. The Fe-C alloy film, up to 200 μm in thickness, showed the hardness of Hv812 at room temperature. Also, the Fe-C alloy had a single martensitic structure, which was tetragonal with a=0.2862 nm, c=0.2910 nm. It was elucidated by ESCA and X-ray diffraction that the alloy did not contain any iron-hydroxides.抄録全体を表示PDF形式でダウンロード (1048K) -
野田 和彦, 小野 一, 水流 徹, 手塚 裕康, 神尾 彰彦1992 年 56 巻 6 号 p. 641-647
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe corrosion behavior of SiC/Al Metal Matrix Composite (MMC) was investigated by polarization measurement and SEM observation. The behavior of SiC/Al MMC was the same as ordinary Al alloys as matrix materials. The anodic polarization curve of SiC/Al MMC in sodium borate-boric acid buffer solution (pH 8.39) containing sodium chloride was very similar to those of ordinary Al alloys. The pitting potential of SiC/Al MMC in each sodium chloride solution was almost the same as that of the ordinary alloys. This fact indicated that the existence of the SiC did not affect breakdown of the passive film.
According to the observation at the SiC/Al interface of model composites which contain macroscopic boundaries, small pits occurred at random over the whole surface after anodic polarization. Occasionally a small number of pits appeared at SiC/Al interface, suggesting the preferential sites for pit growth.抄録全体を表示PDF形式でダウンロード (1534K) -
森 信幸, 秦 弘毅, 大城 桂作1992 年 56 巻 6 号 p. 648-655
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe peritectic solidification process of YBa2Cu3O7−x superconducting oxide was investigated by means of EPMA, SEM, and X-ray diffraction of the specimens quenched during unidirectional solidification. The peritectic reaction of YBa2Cu3O7−x phase (123) occurred from the liquid-Y2BaCuO5 (211) coexisting region mainly by melting the 211 phase with the Ba and Cu enriched liquid ahead of the faceted cellular interface of the 123 phase. The columnar crystals of the 123 phase developed under the solidification condition of G>4×105·R, where G was temperature gradient (K/cm), and R was solidification rate (cm/s). The equilibrium peritectic temperature (Tp) among the 123 phase, 211 and liquid phases was determined as 1280 K±3 K. The crystallization temperature of the 123 phase decreased below Tp with the increase in cooling rate (Vc).抄録全体を表示PDF形式でダウンロード (1389K) -
山内 勇, 大中 逸雄, 小柴 恵一1992 年 56 巻 6 号 p. 656-663
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーA simple and rather quantitative evaluation method for the amorphous formability was proposed. It was estimated by the area fraction of the crystalline part by the optical microscope observation in randomly selected 100 particles from the powder produced by the Rotating-Water-Atomization Process (ROWAP). The applicability of this method was examined by using Co-Cr-P-B alloy particles. The results were as follows.
(1) The results by this method roughly agreeed with that by other methods. In case of the evaluation of amorphous formability of powder or wire, this method may be simpler and more quantitative though it depends on the composition of alloy.
(2) The effect of cooling rate on the amorphous formability was easily estimated by examining the effect of particle diameter or cooling medium in ROWAP.
(3) Amorphous formability depends on the applied prodaction process. Most of results showed that amorphous formability in the single roll process was higher than that in ROWAP. However, it reversed in the case of Fe65Si5B30.
(4) The good amorphous formable composition in (CoCr)80(P, B)20 alloys was Cr=5 to 20 at% for P=5 (B=15 at%). The addition of Cr efficiently increased amorphous formability.
(5) The effect of atomic radius ratio on the amorphous formabilty was not clearly defined in Co-Cr-P-B alloys.抄録全体を表示PDF形式でダウンロード (1255K) -
朱 立群, 渡辺 徹1992 年 56 巻 6 号 p. 664-669
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe structure of Fe-Mo alloy film deposited from strong alkaline bath had been studied in detail. Constituent of the bath, current density and plating temperature were varied to obtain the films with various contents of Mo. This soution is stable and simple. The Fe alloy with Mo up to 20 at% had been obtained. The structure of these alloy films changed by the plating conditions. However, when the content of Mo in the alloy film is in exess of 12 at%, the deposited film had an amorphous structure eventually. To obtain the amorphous alloy deposits, the Mo concentration of the plating bath should be increased higher than 62 kg/m3 and the plating temperature should be lowered below 318 K, respectively, while the current density has no effect on the structure of the film. The amorphous film has very high corrosion resistance in 1N H2SO4 solution compared with the crystallin film.抄録全体を表示PDF形式でダウンロード (1287K) -
駒井 正雄, 高木 研一, 渡辺 忠雄1992 年 56 巻 6 号 p. 670-677
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーWear and corrosion problems become an everyday concern in the extrusion and injection molding process. In this investigation the effect of Ni content on the mechanical properties and structure of the ferrous binder was studied using model alloys whose composition was similar to that of the Mo2FeB2 complex boride base hard alloy applied to the injection molding machine parts. Compacts of the 5B-43Mo-8Cr-xNi-0.1C-bal. Fe model alloys were prepared from mixed and ball-milled powders of Fe-15.1B alloy, pure Mo, pure Cr, carbonyl nickel, carbonyl iron and graphite. The compacts were sintered in vacuum for 1.2 ks at 1523 K. Transverse rupture strength and hardness were measured. The microstructure was investigated by means of SEM, TEM and XRD. Wear and corrosive behaviors of the new hard alloys were also studied. The results are as follows:
The ferrous binder of the model alloys changes from ferritic to martensitic and further to austenitic with increasing Ni content. About 2 mass%Ni content is considered to be the optimal content to obtain the best combination of TRS and hardness associated with the martensitic binder. Abrasive and sliding wear resistances increase with increasing hardness of the tested alloys. The Mo2FeB2 complex boride base new hard alloy, particularly the alloy with the martensitic binder, has better wear resistance than powder metallurgy (PM) high speed steel and an alloy steel SKD11, and is comparable to cemented carbide. The new hard alloys, especially high in Cr and Ni, show excellent corrosive resistance in hydrofluoric acid solution. These results indicate that the Mo2FeB2 complex boride base hard alloys are very suitable material for the injection molding machine parts.抄録全体を表示PDF形式でダウンロード (1829K) -
福本 昌宏, Boulos M. I.1992 年 56 巻 6 号 p. 678-683
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーTi3Al intermetallic compound coating was fabricated just as sprayed conditions by RF plasma spraying without any after heat treatment. Mechanically alloyed Ti-Al powders, which were highly mixed and bonded, were introduced to plasma spraying. DC plasma sprayings were also conducted under various combinations of working gases for the comparison purposes.
The results obtained are summarized as follows.
(1) Ti3Al intermetallic coatings could not be obtained by the DC plasma spray process. The coatings obtained by DC plasma spraying had layer structures of different compositions. Too large acceleration by the DC plasma jet should be attributed to this coating structure.
(2) Ti3Al intermetallic coatings were prepared by RF plasma spraying of MA powders without any after heat treatments.
(3) The feasibility of the combination process of mechanical alloying and RF plasma spraying to fabricate the intermetallic coatings was also discussed.抄録全体を表示PDF形式でダウンロード (1222K) -
佐藤 知絵, 坂本 征彦, 岡村 久宣, 舟本 孝雄, 宮田 寛1992 年 56 巻 6 号 p. 684-690
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーIn order to improve contact resistance between high-Tc superconducting ceramics YBa2Cu3O7−δ and Indium or Indium alloys, interfacial microstructures of the contacts were studied with respect to contact resistance.
YBa2Cu3O7−δ ceramics (YBCO) was prepared by a solid state reaction and sintering of the dry powders at 1223 K. The YBCO/Indium or YBCO/Indium alloy interface was made by soldering below 623 K under ultrasonic exciting loading. In the contact of YBCO/Indium, the microstructure and compounds near the interface were analyzed by SEM-EDX, TEM and XRD, and it was observed that the reacted layer at the interface consists of In2O3 and Ba-In oxides. It is thought that these compounds give a comparatively high contact resistivity of 10−6Ω·m2 order.
Then, in order to make lower the contact resistivity, ten kinds of binary alloys with additives of Pb, Sn and Cd, etc. were used to join with YBCO. Among these alloys, the contact resistivity in the YBCO/In-Cd interfacial layer was very low which is about 10−9∼10−8Ω·m2. One of the compounds in this layer was identified as CdO. The resistivity of CdO was about 10−3Ω·m, much lower than that of In2O3. Therefore we considered that low contact resistance of the YBCO/In-Cd interface is due to the formation of CdO at the reacted layer.抄録全体を表示PDF形式でダウンロード (1066K) -
米谷 茂, 今井 克哉, 能登谷 久公1992 年 56 巻 6 号 p. 691-699
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe specimen of S45C carbon steel was dry ground under various grinding conditions and residual stresses in the ground layer of the specimen were measured. On the measurement of the residual stresses, normal residual stress and residual shearing stress parallel to the grinding direction in each part were measured simultaneously. In order to investigate the influence of the structure on the occurrence of residual stresses, the textures at the ground surface part and at the slightly inner part from the surface of the specimen were measured. The normal residual stress in the ground layer was of tensile character. With increasing work speed or the depth of cut, the normal residual tensile stress in a region from the outer to the inner part increases, while the residual shearing stress in the region decreases slightly. Textures formed at the outermost part in the ground layer were varied with the grinding conditions. The effect of the heat produced in grinding on the occurrence of the residual stresses at the outher part was discussed.抄録全体を表示PDF形式でダウンロード (1266K) -
伊東 明俊, 三輪 敬之, 井口 信洋1992 年 56 巻 6 号 p. 700-706
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーMica glass-ceramics show larger shape recovery than any other ceramics in which the shape memory phenomenon has been observed up to now. The authors directly observed their shape recovery process, assuming that the phenomenon is due to the micro-structure of these ceramics, which is rather different from the others. The process was observed by means of a system, developed by the authors, based on a scanning electron microscope (SEM). This system allows the observation of specimens being heated or cooled inside the SEM. This paper describes the relationship of the process in a micro level according to the observations to the process in a macro level obtained by previous mechanical experiments. The paper also refers to the mechanism of occurrence of the phenomenon. Conclusions are summarized as follows:
(1) Three mica glass-ceramics with different glass-matrix compositions were observed. While a specimen deformed during the heating was reheated, the whole specimen showed recovery. A temperature range in which the recovery cocurred depending on the composition was the same as that derived by the macro level experiments.
(2) Angular change of mica crystals during the reheating, obtained from their VTR images indicated that the crystals which moved complicatedly and ununiformly, interfered with each other.
(3) The crystal network of specimens to which a large amount of torsional pre-deformation had been provided was destroyed, and their mica crystals were dislocated and peeled.
(4) The large recovery of mica glass-ceramics may be ascribed to their mica crystals wholly form a spring net.抄録全体を表示PDF形式でダウンロード (1495K) -
麻生 節夫, 田上 道弘, 後藤 正治1992 年 56 巻 6 号 p. 707-714
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーFe-5%Cr-/15%Cr/25%Cr-C-B alloys having hypoeutectic, eutectic and hypereutectic compositions were solidified in three types molds and their compressive strength, hardness and impact energy were examined. Based on the pseudo-binary eutectic composition, the composition of each alloy was decided in the range from hypoeutectic to hypereutectic by changing the carbon and/or boron content. The solidification rate for each mold was 8.3×10−5∼2.5×10−4 m/s in the unidirectional mold, 4.2×10−4∼5.8×10−4 m/s in the sand mold and ≈5.0×10−3 m/s in the metal mold.
A linear relationship was found to hold between the hardness and the 0.2% proof stress in all the chromium alloy systems. In the hardness range from 50 to 65 HRC, the 0.2% proof stress increased in the order of the 5%, 15% and 25%Cr alloy systems. The effects of boron additions were mainly found on the hardness and the proof stress: particularly 15% and 25%Cr alloys containing boron showed a high hardness value of about 60 HRC and a high proof stress value of about 2000 MPa even in the as-cast condition. This improvement in hardness and proof stress was due to the change of the solidification structure and the bainitic or martensitic transformation of the matrix in the as-cast condition. It was further found that the hypoeutectic and eutectic 15%Cr alloys containing 2% boron have good mechanical properties in the rapid solidification condition for the metal mold.
The reason for avoidance of pearlitic transformation due to the boron addition was thought as follows. Boron reduces the eutectic carbon content and decreases the carbon content of the matrix, so that the avoidance of pearlitic transformation occurs to lead to the increase in Ms temperature. Such a tendency was pronounced especially in the high-chromium alloy system.抄録全体を表示PDF形式でダウンロード (1657K) -
淺香 隆, 岡澤 喜幸, 太刀川 恭治1992 年 56 巻 6 号 p. 715-721
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe Bi-base high-TC oxide superconductors have been synthesized by thermal decomposition of organic acid salt. This process does not require strict pH control unlike other chemical preparation process, facilitating an easy preparation of oxide superconductors. Furthermore, this process allows an uniform and quantitative addition of other elements. The precursor powders less than 10 μm in diameter have been obtained by this process. The powders prepared by the present process exhibit TC’s over 100 K in a shorter sintering time than those prepared by the conventional powder process.
The effects of intermediate process, e.g. pressing and grinding between heat-treatment cycles, on superconducting properties and grain morphologies were investigated. The TC’s are appreciably increased by an intermediate pressing, and reduced by intermediate grinding. The TC of 109 K has been obtained by intermediate pressed specimens, with total heat-treatment time of 60 h. The maximum JC (77 K) so far obtained in the sintered specimen is 1540 A/cm2.
The X-ray diffraction analyses performed on these specimens reveal that the intermediate pressing enhances the diffraction peaks of high-TC phase, with strong (00l) orientation, and suppresses those of low-TC phase. Meanwhile, the diffraction peaks of high-TC phase are reduced by the intermediate grinding. The changes in TC and JC by the intermediate pressing and grinding have been discussed relating to the structure changes. The Bi-base oxide powders prepared by the present process may be useful for the conductor fabrication.抄録全体を表示PDF形式でダウンロード (855K) -
淺香 隆, 塩見 泰章, 太刀川 恭治1992 年 56 巻 6 号 p. 722-728
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe Y-base high-TC oxide superconductors have been synthesized by an organic acid salt thermal decomposition process. This process allows the addition or substitution of other elements easily and quantitatively. The precursor powder less than 10 μm in diameter have been obtained by this process.
The effects of Ag addition and Zr substitution for Y on superconducting properties and structures of high-TC YBa2Cu3O7−x (123) oxide were studied. TC ’s of 92 K have been obtained after a relatively short sintering in the 123 specimen. The addition of 10∼30 mass%Ag decreases the optimum sintering temperature to achieve highest TC by ∼50°C. The 5 at%Zr substitution for Y produces much smaller 123 grains with uniform grain size. Both the Ag addition and the Zr substitution enhance the JC (77 K) of the 123 specimen by a factor of several. The refinement of 123 grains and the dispersion of fine Ag particles seem to attribute to the enhancement in JC.
Furthermore, effects of simultaneous substitution of Zr and addition of Ag were also studied. The decrease of optimum sintering temperature is observed like Ag-added 123 specimens. A JC (77 K) of 300 A/cm2 has been obtained after the sintering at 880°C for 4 h. The Zr substitution reduces the rapid decrease of JC by the prolonged sintering in the Ag-added specimen.
The X-ray diffraction analyses were performed on these specimens. The diffraction peaks of 123-phase and Ag are obtained in the Ag-added specimens, while those of 123-phase and orthorhombic ZrO2 are obtained in the Zr-substituted specimens.抄録全体を表示PDF形式でダウンロード (1286K) -
古牧 政雄, 西村 睦, 天野 宗幸1992 年 56 巻 6 号 p. 729-733
発行日: 1992年
公開日: 2008/04/04
ジャーナル フリーThe effects of solute oxygen atoms on the hydrogen permeability and diffusivity in V-15 at%Ni alloy membranes have been investigated. In order to remove the solute oxygen atoms, a suitable amount of the deoxidizer such as Y, Ti, or Zr was added during arc-melting the alloy. The hydrogen permeability and diffusivity of the alloy samples plated with Pd were determined using the gas permeation and time-lag methods in the temperature range 373 to 673 K. The samples added a suitable amount of Y, Ti or Zr showed higher hydrogen permeabilities and diffusivities above 473 K, than a sample without the deoxidizer. Below about 473 K, however, these samples showed a hydrogen trapping phenomenon, just like a sample without the deoxidizer. It is considered that solute oxygen atoms in the alloy decrease the effective area for hydrogen permeation. The hydrogen trapping phenomenon observed below about 473 K is considered to be caused mainly by surface effects.抄録全体を表示PDF形式でダウンロード (661K)
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