巻号一覧
59 巻, 2 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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高橋 裕1995 年 59 巻 2 号 p. 117-124
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーAn epitaxial C60/C70 film with the (111)fcc\varparallelsubstrate surface was deposited on a mica substrate heated to 573 K. Transmission electron microscopy revealed straight contrasts parallel to the ⟨1\bar10⟩ directions (defect A) and irregularly curved contrasts (defect B) in the film.
(a) The film contained a lot of doubly-positioned twins (or 180° rotation twins about the [111] axis, while there was none of other ⟨11\bar1⟩-axes). Some of defects B were twin boundaries between the doubly-positioned twin domains. A few of defects A were {11\bar2} incoherent twin boundaries.
(b) Most of defects A and B were identified as stacking faults. Defects B were conposed of a complex of stacking fault jogs.抄録全体を表示PDF形式でダウンロード (2101K) -
酒井 拓, 徐 洲1995 年 59 巻 2 号 p. 125-132
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーEffect of purity on static softening and grain growth taking place after dynamic recrystallization (DRX) was studied by means of interrupted compression tests and metallographic observations for the three kinds of polycrystalline coppers, the purities of which were 99.9(3N), 99.99(4N) and 99.9999(6N) mass%. The fractional softening-holding time (X-t) curves after dynamic recovery consist of two stages, followed by complete softening. In contrast, the softening curves for DRX matrices consist of three distinct stages accompanied with three plateaus, followed by incomplete softening (stage I, II and III). The X-t curves for DRX 3N and 4NCu are almost the same, but clearly different from that for 6NCu. The static softening for DRX 6NCu takes place one order of magnitude faster than that for 3N or 4NCu and finally approach X=1 after a long period of annealing time in stage III. The average rate of grain growth in stage III is always smaller than that for normal grain growth, although both the rates are controlled by grain boundary diffusion irrespective of purity of copper. This results from the stable existence of metadynamically recovered grains which have many-sided irregular shapes as well as high density dislocations. As these grains are metastable in thermodynamics, however, DRX matrices only for 6NCu finally replace fully recrystallized ones, followed by the occurrence of normal grain growth.抄録全体を表示PDF形式でダウンロード (1286K) -
浜石 和人, 末吉 秀一, 清藤 純一, 中村 祐三1995 年 59 巻 2 号 p. 133-139
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーIn order to develop a method of gas nitriding of austenitic stainless steels without surface treatment such as pickling, three types of steels, SUS304, SUS316 and SUS310, were pre-treated under various mechanical processes (as-cut with resinoid blade, polishing with emery papers, grinding with CBN wheel, and shot peening), followed by nitriding in NH3 gas with a flow rate of 2.8 m3/h at 843 K for 20 h. The influence of the mechanical pre-treatment on nitriding behavior was examined in connection with two factors of surface roughness and strain-induced martensite.
Nitriding reaction depends primarily on surface roughness in SUS310 and SUS316. This nitriding reaction is enhanced markedly with increasing surface roughness when its value exceeds 6 and 1 μm for SUS310 and SUS316, respectively, while no reaction is recognized for the surface roughness less than these values. In SUS304, martensitic transformation is induced readily by the mechanical pre-treatment, and not only the surface roughness but also the strain-induced martensite contribute to nitriding behavior.
It is confirmed from the present results that mechanical pre-treatment enables the gas nitriding of austenitic stainless steels without pickling, when the surface roughness and the amount of strain-induced martensite are controlled properly.抄録全体を表示PDF形式でダウンロード (652K) -
蔭山 健介, 榎 学, 岸 輝雄, 生稲 一洋, 木村 光1995 年 59 巻 2 号 p. 140-144
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーCeramics particulate glass matrix composites are attracting attention as materials for highly dense multilayered substrates. The low fracture strength and toughness of glass, however, present a problem. The influence of several dispersed particles on microfracture therfore was studied for ceramic particulate glass matrix composites. The four-point bending and fracture toughness (SEPB) tests were carried out in vacuum, air and water, and the AE was measured at the four-point bending test and analyzed one dimensional AE location. As results, the microfracture process was changed, depending on the thermal expansion and the elastic modulus of dispersed particles. For alumina particulate glass matrix composites, the microcracking did not occur after the final fracture, because microcracks already occurred during the fabrication due to the thermal expansion mismatch between dispersed particles and glass matrix. For cordierite and silica glass particulate glass matrix composites, on the other hand, adequate microcrackings (100-200 AE events) occurred at loading and the microcrack toughening enhanced. Furthermore, the microcrack toughening did not improve the average bending strength, but the scatter of bending strength decreased significantly.抄録全体を表示PDF形式でダウンロード (475K) -
松木 賢司, 村上 哲, 松本 博明, 時澤 貢, 高辻 則夫, 磯貝 光之1995 年 59 巻 2 号 p. 145-151
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーExtremely fine grained 7075 aluminum alloys reinforced with SiC particulates, of which volume fractions are 5, 10, and 15%(MA7075+5SiC, +10SiC, +15SiC composite, respectively), have been developed by using mechanical alloying process. Superplastic properties of these composites have been investigated at the initial strain rates ranging from 10−5 s−1 to 2×10 s−1 at a temperature of 793 K.
In log flow stress-log strain rate curves for the three composites, two strain rate regions showing low and high strain rate sensitivity exponent, m, (region 1 and 2, respectively) were recognized, as in usually observed in superplasticity. At very high strain rates from 5×10−1 to 2×10 s−1 (region 2), values of m were larger than 0.36, and superplastic elongations were larger than 200% in the three composites. In contrast, m values were less than 0.13 at lower strain rates (region 1), where low elongations (<50%) appeared. With increasing of the SiC particulate content, region 2 moved to the range of higher strain rate. Grain boundary sliding took place more remarkably in region 2 rather than in region 1.
The threshold stress, σth, estimated by using an extrapolation method increased with increasing of the SiC content. A double logarithmic plot of the strain rate and the effective stress, σe(=σ−σth), can be approximated by straight lines with a slope of about 0.5 for MA7075+SiC composites, which suggests the superplasticity of the composites to be explained by the grain boundary sliding model accommodated by dislocation slip. The SiC particulates on grain boundaries can resist the boundary sliding, thus resulting the threshold stress, σth.抄録全体を表示PDF形式でダウンロード (1089K) -
森川 龍哉, 竹盛 英昭, 中島 英治, 吉永 日出男1995 年 59 巻 2 号 p. 152-155
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーIt has been examined whether the macroscopic electric resistivity that reflects the microscopic internal structure is applicable as the discrimination method of the change of high-temperature deformation mechanism with the increase of strain-rate in solution-hardened alloys.
When specimens were held at 473 K after introducing dislocations by deformation at room temperature, the resistivity decreased rapidly in a short time, suggesting that the decrease should include the effect of solute atmosphere formation around dislocations.
When specimens were deformed by tension at 573 K with various strain rates and rapidly cooled, the resistivity measured at room temperature and at 77 K depended on the flow stress, and the dependence reversed at the breakaway stress of dislocation from their solute atmospheres. Changes in resistivity are discussed relating to the decrease due to atmosphere formation and the increase due to the increase of dislocation density.抄録全体を表示PDF形式でダウンロード (361K) -
金森 賢樹, 杉浦 正仁, 不破 章雄1995 年 59 巻 2 号 p. 156-163
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーThe equilibria in the Si(s)-Cl2(g) system have been studied at temperature from 1000 to 1300 K using a transpiration reactor. The equilibria are considered among Si(s)-Cl2(g)-SiCl2(g)-SiCl3(g)-SiCl4(g). The standard Gibbs energies of formation for the species of SiCl2(g) and SiCl3(g) species at these temperatures are determined simultaneously, where these subchloride species coexist in appreciable quantities with SiCl4 in the gas phase at these temperatures, as follows:
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上田 康, 土居 定雄1995 年 59 巻 2 号 p. 164-168
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーThe interdiffusivity of FeO-CaO in the liquid FeO-CaO-SiO2 slag contained in an iron crucible has been measured in the temperature range 1573 to 1673 K using the electrochemical method. The experimental technique was the chrono-potentiometry at constant currents using the following cell:
(This article is not displayable. Please see full text pdf.)
\ oindentSlags contain 21 to 32 mol%FeO and 32 to 52 mol%SiO2.
The interdiffusivity varies from 1.6×10−11 to 3.9×10−10 m2 s−1 at 1573 K, 2.7×10−11 to 5.8×10−10 m2 s−1 at 1623 K and 4.3×10−11 to 8.9×10−10 m2 s−1 at 1673 K, depending on the silica content of the slag. The interdiffusivity is inversely proportional to the viscosity. These results show that the interdiffusivity is governed by the silicate structure and the amount of silicate.抄録全体を表示PDF形式でダウンロード (369K) -
佐貫 須美子, 杉山 明夫, 門町 清隆, 宮田 敬介, 新井 甲一1995 年 59 巻 2 号 p. 169-176
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーA possibility to develops a wet method, consisting of leaching, solvent extraction and precipitation, to recover metal values from scrap Sm-Co magnets including SmCo5 and Sm2Co17 was investigated.
All component metals are readily leached out in 2 kmol·m−3 HNO3 solution. By contrast, HCl and H2SO4 are less effective leachants, leaving Cu in the leach residue. Firstly Fe(III) and Zr(IV) were extracted in an organic phase with D2EHPA from the leach solution, then Sm(III) was extracted with the same extractant after pH adjustment. Precipitation stripping of Sm(III) with oxalic acid was found to be effective in avoiding the co-precipitation of other metals. Cu(II) and Co(II) in the raffinate can be extracted with LIX65N and D2EHPA, respectively, and stripped with an aqueous H2SO4 solution. Fe(III) and Zr(IV)-loaded D2EHPA organics can be stripped with oxalic acid, followed by the photo-chemical reduction of Fe(III)-oxalate to the Fe(II) state to selectively precipitate, leaving Zr(IV) oxalate in the stripped solution. Based on these findings, a novel process was proposed with the values of expectant material balance.抄録全体を表示PDF形式でダウンロード (857K) -
奥宮 正洋, 恒川 好樹, 新美 格, 室賀 啓, 丸山 浩二1995 年 59 巻 2 号 p. 177-182
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーLow crabon steel (S15CK) specimens were oxy-nitrided in nitrogen-ammonia-carbon dioxide mixed gas atmosphere. The microstructures of oxy-nitrided surface layers were examined by optical microscope, X-ray microanalysis and X-ray diffraction. Corrosion-resistance and wear-resistance of oxy-nitrided layers were also studied. The gas composition greatly affects the microstructure of oxy-nitrided surface layers, which is classified into white layer, gray layer with white layer and gray layer. The white nitride layer is composed of an ε phase, Fe3N and γ′ phase. The main constituent of the white layer containing higher nitrogen is ε, and that with lower nitrogen is γ′. The main constituent of the gray layer is found to be Fe3O4. The thickness of oxide layer increases as the premixed ammonia ratio decreases or the premixed carbon dioxide ratio increases through activated oxidation. With less than 45 vol% ammonia ratio and high carbon dioxide atmosphere, the oxy-nitrided layer is composed of only Fe3O4. The white nitride layer, ε, Fe3N and γ′ shows good corrosion resistance. The thickness of nitrided layer decreases as the premixed carbon dioxide ratio increases and the thin gray Fe3O4 layer formed on the nitride layer. These layers show bad corrosion resistance. But the thick gray Fe3O4 layer shows good corrosion resistance. Wear-resistance of oxy-nitrided steels is improved about fourfold compared with untreated specimens. The nitride layer shows good wear resistance and it slightly decreases as the thin gray Fe3O4 layer formed on the nitride layer.抄録全体を表示PDF形式でダウンロード (759K) -
佐治 重興, 橋本 和弥, 根石 豊, 荒木 秀樹, 山根 壽己1995 年 59 巻 2 号 p. 183-190
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーThe mechanical alloying(MA) process of Al-6 at%Ti mixed powders under a surging mode of a high energy planetary ball mill in Ar gas, at the maximum centrifugal acceleration of 40, 80, 120 and 150 G(G is the gravitational acceleration), was investigated by means of microscopic observation, X-ray diffraction, hardness measurement and quantitative analysis of the composition. The MA process proceeds in the following three stages; At the 1st stage both the coalescence of Al and Ti elemental powders and adhering on the pot-wall and the surface of balls occur. The amount of such adhesions increases with milling time. At the 2nd stage, almost all Al-Ti mixed powders adhere on the pot-wall and the ball surfaces, and the dissolution of Ti and Fe atoms into Al powders, work-hardening and the refining of the crystal grains to the nano-size proceed under compressional, frictional and shearing stresses, due to the surging motion of the milling balls. At the 3rd stage, the hardened(Hv: 400∼500) powders, consisting of nano-size crystals of Al-6 at%Ti-1 at%Fe supersaturated solid solution, fall down from the pot-wall and the ball surfaces during milling. In the 3rd stage, the higher the MA energy, the larger the amount of the powders obtained and the greater the hardness of the powders. At the same time, the higher milling intensity caused the faster progress of the MA process. The average grain size of the Al-6 at%Ti-1 at%Fe alloy powders milled for a long time is from 13 to 17 nm, depending on milling intensity during MA. Higher milling intensity tends to bring a smaller grain size. No amorphous phase is detected.抄録全体を表示PDF形式でダウンロード (901K) -
宇都宮 裕, 斎藤 好弘, 左海 哲夫, 森田 耕成1995 年 59 巻 2 号 p. 191-197
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーA commercial purity aluminum (JIS A1050) and a Al-Mg alloy (A5052) strips 1.94 mm in thickness and 20 mm in width were rolled and annealed. The lateral spread in rolling was varied by rolling methods. The satellite-mill rolling, a conventional caliber rolling and a conventional flat rolling were applied. The pole figures and mechanical properties of strips were measured. Deep drawing of the annealed strips was conducted, and earing of drawn cups were observed. The infuence of lateral spread in rolling on the textures and on mechanical properties of the strips were investigated.
The main results obtained were as follows. (1) The rolling texture approaches fiber texture ⟨110⟩\varparallelN.D. with increasing lateral spread. (2) In the recrystallization textures, the ⟨100⟩{001} cube texture components decreased with lateral spread, (3) The earing height of the drawn cups decreased with lateral spread, These results means that the planar anisotoropy of strips decreased with the lateral spread in rolling.抄録全体を表示PDF形式でダウンロード (516K) -
戸田 裕之, 小林 俊郎, 和田 義治, 井上 直也1995 年 59 巻 2 号 p. 198-205
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーRecently we have constructed a simulation program based on the fracture mechanics for crack initiation and growth in discontinuously-reinforced MMCs.
Parametric studies are carried out to evaluate the effects of reinforcement properties, such as volume fraction, tensile strength, interfacial bonding stress and spatial pattern of distribution, on crack initiation and growth characteristics through SiC whisker-reinforced 6061Al alloy composites. The crack initiation toughness decreases and simultaneously the crack growth resistance increases with increasing volume fraction. Degradation of both interfacial bonding stress and fiber strength affect mostly the crack initiation toughness. On the other hand, spatial patterns of whisker distribution have a certain influence on crack growth resistance, and there exists an optimum extent of whisker clustering for the crack growth resistance.
Based on the results of the simulation, MMC with artificial and periodic clustering of whiskers has been proposed. It has been fabricated actually by high pressure infiltration casting using preforms made from granulated whiskers, and its mechanical properties and fracture characteristics are evaluated. It is certain that the crack growth resistance of the MMC is improved without spoiling other mechanical properties by introducing clustering.抄録全体を表示PDF形式でダウンロード (1045K) -
福田 泰隆, 下斗米 道夫1995 年 59 巻 2 号 p. 206-212
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーThe mechanism of corrosion-improvement in Nd-(FeCoNiTi)-B type sintered magnets has been clarified by a corrosion and electrochemical tests on sintered specimens and single phase specimens of 2-14-1 phase and grain boundary phases such as Nd-rich and B-rich phases. In pH=2.7 solution, the vanishingly small difference of corrosion potentials between 2-14-1 and Nd-rich phases in the above magnets suppresses the formation of galvanic cell and consequently inhibits intergranular corrosion. In solutions with pH larger than 5.8, the intergranular corrosion is inhibited by the passive oxide film of Nd-rich phase. As far as intergranular corrosion is concerned, it is inhibited in pH=2.7 acid solution due to the enhanced corrosion potential for 2-14-1 phase. For solutions with pH larger than 5.8, it is suppressed by the formation of the passive oxide film of 2-14-1 phase. As regards the effects of Co and Ni substitution for Fe, the Co and Ni atoms contribute to the enhancement of the corrosion potential in pH=2.7. The effect of Ni atoms on the improvements of the corrosion and pitting potential is estimated to be 4 times larger than that of Co atoms for solutions with pH larger than 5.8.抄録全体を表示PDF形式でダウンロード (1036K) -
井口 征夫, 鈴木 一弘, 小林 康宏1995 年 59 巻 2 号 p. 213-218
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーIn order to investigate the influence of magnetic properties of TiN-coated silicon steel sheet due to the difference of PVD coating methods, which were the hollow cathode discharge(HCD) and electron beam(EB)+radio frequency(RF) methods, TiN coating has been done inside the PVD apparatus. The magnetic properties of the TiN-coated silicon steel sheets after ceramic coating were evaluated. Measurements by thin-film X-ray diffraction, color monitoring, Ti/N analysis and observations of the three-dimensional scanning electron microscope and magnetic domain were also carried out.
The experimental results obtained are summarized as follows.
(1) The magnetic flux density [B8(T)] and iron loss [W17⁄50(W/kg)] of the TiN-coated silicon steel sheets deposited by the PVD method were improved dramatically in good agreement with the previous experimental results, but the degree of improvement of B8(T) and W17⁄50(W/kg) by the HCD method was about twice as large as that by the EB+RF method.
(2) This improvement in magnetic properties in both HCD and EB+RF methods was most marked in silicon steel sheets with the highest magnetic flux density.
(3) For example, in the silicon steel sheet with B8=1.93 T, the changes in ΔB8(T) and ΔW17⁄50(W/kg) after TiN ceramic coating by the HCD method were 0.007 T and 0.15 W/kg, respectively, while those by the EB+RF method were 0.003 T and 0.08 W/kg.
(4) Thin-film X-ray diffraction inspection by the HCD method indicated a strong peak of (111) of TiN, while that by the EB+RF method indicated comparatively strong (200), (111) and (110) peaks and weak (311) and (222) peaks.
(5) It is considered that, due to a higher ionization of the HCD method than that of the EB+RF method, it is possible to give a strong surface tension to the near-surface of the TiN-coated silicon steel sheet, to which a fine, smooth TiN film with good adhesion has been coated, and thereby it can improve the iron loss drastically.抄録全体を表示PDF形式でダウンロード (741K) -
兜森 俊樹, 竹田 晴信, 脇坂 裕一, 大西 敬三1995 年 59 巻 2 号 p. 219-228
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーHydrogen absorption alloys are functional materials that can be used for thermal and mechanical energy conversion by utilizing the heat of reaction in hydrogen absorption and desorption. On the other hand, they show greater or lesser degradation behavior in a hydriding capacity resulting from absorption and desorption cycling. The degradation by cycling is divided into two phenomena: intrinsic degradation attributed to the structural or phase changes of the alloy, and extrinsic degradation due to the surface contamination of the alloy by gaseous impurities in hydrogen gas. In LaNi5 having a CaCu5 structure, it has been recongnized that the intrinsic degradation is relatively large. In the present study, the intrinsic degradation of CaNi5 having the same structure as LaNi5 was examined with respect to the effects of temperature and Mm and/or Al substitution for Ca and Ni on the degradation properties of the CaNi5.
The intrinsic degradation of CaNi5 was slightly larger than that of LaNi5. The temperature dependence of the degradation, which becomes larger with rising temperature, was exhibited clearly and quantitatively. Al substitutions for Ni were shown to prevent the degradation of CaNi5. The number of cycles needed to achieve 50% degradation of the initial capacity of (CaMm) (NiAl)5 alloy at a temperature below 333 K was over 50,000. Consequently the (CaMm) (NiAl)5 alloy seemed to have an excellent cycle life for use in a practically absorption and desorption cycling system. From observation of the fully degraded CaNi5 sample using transmission electron microscopy, the grain sizes of the CaNi5 crystals were recognized to be about 10 nm in diameter. Accordingly, the mechanism of intrinsic degradation of CaCu5-type alloy by absorption and desorption cycling was inferred to be the disordering of crystal structure by reduction of the grain size of the crystal, in a manner different from disproportionation.抄録全体を表示PDF形式でダウンロード (1202K) -
岡崎 義光, 太田 学, 伊藤 喜昌, 立石 哲也1995 年 59 巻 2 号 p. 229-236
発行日: 1995年
公開日: 2008/04/04
ジャーナル フリーThe corrosion resistance of implant alloys was investigated by anodic polarization measurements in pseudo physiological solution. Role of alloying elements in passive film formed on implant alloys by the anodic polarization was also examined with X-ray photoelectron spectroscopy (XPS). Passivity zones of SUS316L stainless steel and Co-Cr alloys are narrow, and a rapid increase of current density results from the low potential in comparison to Ti alloys. The passive current density of Ti-15%Zr-4%Nb-2%Ta-0.2%Pd alloy (mass%) is very low. Effects of protein and dissolved oxygen with 90%N2+5%CO2+5%O2 gas bubbling on anodic polarization curves are not detected. The passive film formed on the Ti-6%Al-4%V extra low interstitial alloy consist mainly of TiO2, Al2O3 and small amounts of V oxide. Passive films on Ti-15%Zr-4%Nb-2%Ta-0.2%Pd and Ti-15%Sn-4%Nb-2%Ta-0.2%Pd alloys consist of TiO2, ZrO2, SnO2, Nb2O5, Ta2O5 and PdO or Pd. XPS spectra from the Co-Cr alloy and SUS316L stainless steel show peaks of Cr2O3, CoO, Fe oxide, Mo oxide, Ni, Co, Fe, Mo and Cr. As Ni, V and Co are strong cytotoxic elements, it was found that biocompatibility of SUS316L, Co-Cr, Ti-6%Al-4%V ELI alloys become lesser after a long time use in the living body. The thickness of the passive film on Ti alloys is thinner than that of Co-Cr alloy. Passive film formed on Ti-15%Zr-4%Nb-2%Ta-0.2%Pd alloy is strong and stable.抄録全体を表示PDF形式でダウンロード (1173K)
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