巻号一覧
54 巻, 5 号
選択された号の論文の18件中1～18を表示しています
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坂田 孝夫, 角田 直人, 藤田 広志1990 年 54 巻 5 号 p. 495-501
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーElectron irradiation at a low temperature produces the amorphous phase in NiTi alloy. The crystallization process of the amorphous phase was studied by means of in-situ experiment using HVEM. It is divided into three characteristic stages of the crystallization process. First, the broad and obscure boundary between the amorphous and the crystalline region becomes narrower and clearer. Second, the small crystals appear in the amorphous region near the boundary at 523 K. They grow towards the centre of the amorphous region with increasing the annealing temperature and the annealing time. The orientations of individual crystals are almost the same as the orientation before the irradiation.抄録全体を表示PDF形式でダウンロード (3169K) -
李 成烈, 飯島 嘉明, 田口 牧, 平野 賢一1990 年 54 巻 5 号 p. 502-508
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーInterdiffusion coefficients in the β-phase Ti-Cu and Ti-Ag alloys have been determined by Matano’s method in the temperature range between 1173 and 1773 K with (pure Ti)-(Ti-2.28 at%Cu alloy) and (pure Ti)-(Ti-2.76 at%Ag alloy) couples. In both alloys the interdiffusion coefficients have been shown to be independent of concentration of solutes, and then the impurity diffusion coefficients of Cu and Ag in β-Ti have been estimated by extrapolating the interdiffusion coefficient to infinite dilution of the solute in each alloy. The diffusion coefficient of Ag, \ ildeDAg(0), in β-Ti is of nearly the same magnitude as the self-diffusion coefficient of β-Ti, DTi∗, and the Arrhenius plot of \ ildeDAg(0) shows a significant curvature, as in the case of the self-diffusion in β-Ti. On the other hand, the diffusion coefficient of Cu, \ ildeDCu(0), in β-Ti is larger than DTi∗ by about one order of magnitude, and the Arrhenius plot of \ ildeDCu(0) shows also a curved line but the curvature of it is slightly looser than that in the case of \ ildeDAg(0). The curved Arrhenius plots can be explained by a monovacancy mechanism with a temperature dependent migration energy due to the softening of the LA 2/3 ⟨111⟩ phonon mode in β-Ti. It has been noted that the activation energy for the impurity diffusion of Cu and Ag and self-diffusion in β-Ti is proportional to the square of radius of the diffusing atom.抄録全体を表示PDF形式でダウンロード (837K) -
原勢 二郎, 清水 亮, 富増 国年, 高橋 延幸1990 年 54 巻 5 号 p. 509-516
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーGrain boundary character distribution and texture evolved during α-γ-α tarnsformations of (110)[001] iron single crystal were investigated by X-ray and SEM-ECC (Electron Channeling Contrast)-ECP (Electron Channeling Pattern) techniques. The main conclusions obtained are as follows.
(1) Grain boundaries with Σ1 and Σ3 were evolved with higher frequency by α-γ-α transformations.
(2) Origin of Σ3 boundaries were considered to be annealing twins formed in the γ phase region.
(3) Σ1 and Σ3 boundaries evolved by transformations, especially Σ1 boundaries were stable in the subsequent annealing in the α phase region.
(4) Textures evolved by α-γ-α transformations were associated with orientations calculated by the K-S orientation relationship.抄録全体を表示PDF形式でダウンロード (3100K) -
原勢 二郎, 清水 亮, 清水 康宏, 岩山 健三, 住友 秀彦1990 年 54 巻 5 号 p. 517-524
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーGrain growth behavior in Fe-50%Ni has been investigated by SEM-ECC(Electron Channeling Contrast)-ECP (Electron Channeling Pattern). The main conclusions obtained are as follows.
(1) Frequency of Σ1 boundaries were highest (about 50%) among other boundaries in a primary recrystallized stage and frequency of Σ3 and Σ9 boundaries increased and that of the Σ1 boundaries decreased by secondary recrystallization. The decrease in the frequency of Σ1 boundaries was mainly due to the secondary recrystallization of orientations having the Σ7 or Σ19b orientation relationship in relation to these grains with Σ1 boundaries. The increase in the frequency of Σ3 and Σ9 boundaries was found to be due to the evolution of annealing twins into these secondary recrystallized grains and the evolution of annealing twins into these annealing twins, respectively.
(2) It is possible to predict secondary recrystallization texture by measuring orientation of several hundreds grains before grain growth and analyzing frequency of grains with the coincidence orientation relationship in relation to hypothetical orientations arbitrarily chosen and orientations of annealing twins.抄録全体を表示PDF形式でダウンロード (1979K) -
足立 吉隆, 和出 昇, 細井 祐三1990 年 54 巻 5 号 p. 525-531
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーA study has been made of the effect of hydrogen on the shape memory effect and transformation behavior of Ti-Ni alloy. The material was evaluated in the temperature range from 300 to 473 K using a bent specimen. The transformation behavior was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction technique.
The results obtained are as follows:
(1) The shape recovery rate is markedly decreased by a small amount of hydrogen which does not cause the increase in hardness.
(2) The shape recovery occurs even below the transformation temperature (As) in the material charged with hydrogen for a relatively long time, resulting from a hydride formation.
(3) It is found that the hydrogen causes a considerable decrease in the heat of the transformation and only a slight decrease in the transformation temperature.
(4) The heat of transformation and the transformation temperatures before hydrogenation is restored by holding the hydrogenated material at 753 K for 300 s.
(5) Two types of the hydrides form during charging at a current density of 1000 A/m2.抄録全体を表示PDF形式でダウンロード (677K) -
中佐 啓治郎, 清瀬 啓輔, 劉 建平1990 年 54 巻 5 号 p. 532-538
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThree-point bending tests were carried out on the Ti-6Al-4V alloy specimens which were cathodically hydrogen-charged under different current densities in sulfuric acid solution. The effect of hydrogen charging time and hydride formation on the bending strength was investigated by X-ray diffraction study.
When the charging current density ic was 3000 A/m2, the bending strength σb and the deflection at maximum load δmax decreased to show a minimum at the beginning of hydrogen charging, then increased to reach a maximum, and decreased again with further increasing hydrogen charging time tc. In the cases of lower current densities (ic=500 and 1000 A/m2), on the other hand, such a phenomenon was not obvious and σb decreased rather monotonically with increasing tc. The relation between tc and the amount of hydride formed on the specimen surface was almost opposite to that between tc and σb. The reason for the appearance of maximum on tc vs. σb curve under the higher current density seemed to be that the hydride had decomposed by the generation of compressive stresses above a certain value near the specimen surface due to the expansion of hydride.抄録全体を表示PDF形式でダウンロード (873K) -
橋本 健紀, 土肥 春夫, 笠原 和男, 辻本 得蔵, 鈴木 朝夫1990 年 54 巻 5 号 p. 539-548
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe mechanical properties of Ti-33∼38 mass%Al alloys containing Mn up to 3.5 mol% has been examined by hardness, compression and bending tests. The microstructures were examined using a optical microscope, an electron probe microanalyzer and an X-ray diffractometer. The deformation structures were also examined by a transmission electron microscope and a scanning electron microscope.
The ductility at room temperature increases in the alloys having the atom ratio of Al/Ti smaller than unity and containing less than 2.5 mol%Mn. The best ductility is obtained at the composition of Ti-34.5 mass%Al-1.45 mass%Mn (Ti-48.4 mol%Al-1.0 mol%Mn). The elongation of the alloy is estimated to be over 3% from the bending test result, when the alloy is heat-treated at 1273 K for 605 ks. The softening of the TiAl phase is found in the alloys showing good ductility.
The factors improving ductility of the alloys are considered mainly to be the softening of the TiAl phase and partly the fineness of the microstructure by the addition of Mn. The softening of the TiAl phase is attributed to the decreases of the deformation stress due to the increase of twinning deformation. Hence it is concluded that the improvement of ductility of the alloys is attained by the increase of the stress difference between deformation and fracture.抄録全体を表示PDF形式でダウンロード (3145K) -
真保 良吉, 中村 泰1990 年 54 巻 5 号 p. 549-555
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーStandard Gibbs free energy changes for the syntheses of YBa2Cu3O6.5+x, (a high temperature superconductor), Y2BaCuO5, and Y2Cu2O5 were investigated by using chemical thermodynamic methods.
For the reaction where YBa2Cu3O6.5+x was synthesized from a Y2Cu2O5-BaCO3-CuO mixture with CO2 evolution, the relationship between the equilibrium temperature and the partial pressure of CO2 was examined by the thermogravimetric analysis. The equilibrium temperature (1080-1190 K) was determined by observing the change of sample weight at a given temperature in a stream of a CO2-O2-N2 gas mixture. The relationship between the equilibrium temperature and the partial pressure of CO2 for a Y2BaCuO5-BaCO3-CuO-YBa2Cu3O6.5+x mixture was also examined by the same method and it was confirmed that the mixture was more stable than a Y2Cu2O5-BaCO3-CuO-YBa2Cu3O6.5+x mixture in the equilibrium state.
A similar experiment was performed for the synthesis of Y2BaCuO5 from a Y2Cu2O5-Y2O3-BaCO3 mixture in a temperature range 1090-1210 K.
Measurements of electromotive force of the galvanic cell with a zirconia solid electrolyte were conducted for the synthesis of Y2Cu2O5 from Y2O3 and CuO. The construction of the galvanic cell was Pt|Y2Cu2O5, Y2O3, Cu2O |ZrO2, (Y2O3)|CuO, Cu2O|Pt, and the standard Gibbs free energy change for the synthesis of Y2Cu2O5 was derived from the partial pressure of O2 in the equilibrium among Y2Cu2O5, Y2O3, and Cu2O in a temperature range 1025-1220 K.
By combining these results, the standard Gibbs free energy changes for the synthesis of YBa2Cu3O6.5+x and Y2BaCuO5 from Y2O3, BaCO3 and CuO were obtained.抄録全体を表示PDF形式でダウンロード (875K) -
武部 博倫, 森永 健次1990 年 54 巻 5 号 p. 556-561
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe condition to get a cordierite (2MgO·2Al2O3·5SiO2) ceramics by the solidification of the melt has been discussed. Cordierite was not crystallized but mullite, protoenstatite, etc, with the decomposition from its super-cooled liquid under the continuous cooling process. “Low”-cordierite and μ-cordierite, however, were identified in the process of the isothermal transformation at 1623∼1673 K and 1223∼1253 K, respectively. The μ-cordierite was transformed to the α-cordierite with increasing holding time of sample at 1223∼1253 K. TTT diagram in the solidification of cordierite melt was measured. From the result of TEM, planar faults and dislocations were observed as the microstructure of α-cordierite, so that the transformation of μ-cordierite to α-cordierite was similar to the isothermal martensite transformation that occurred in the carbon steel.抄録全体を表示PDF形式でダウンロード (1154K) -
斎藤 秀俊, 弘津 禎彦, 一ノ瀬 幸雄1990 年 54 巻 5 号 p. 562-567
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーFormation and deposition processes of boron nitride (BN) films are discussed. BN films were sythesized from boran-ammonia (BH3NH3) with a 4-coordinated structure by RF plasma CVD with tungsten filament heating. The deposited BN films are structurally cubic (four-coordinated) or turbostratic (three-coordinated), which strongly depends on the tungsten filament temperature, total gas pressure and RF power. That is, BH3NH3 can be changed to both cubic and turbostratic structures.
The etching rate of turbostratic BN (t-BN) increases with increasing emission intensity I(Hα) in the gas plasma, where I(Hα) is the spectral intensity at the wavelength of 656 nm corresponding to the emission from the atomic hydrogen by plasma excitement and filament heating. The atomic hydrogen causes the preferential chemical ecthing of t-BN, thus contributing greatly to the growth of cBN in the films.抄録全体を表示PDF形式でダウンロード (963K) -
森下 政夫, 河合 伸泰, 吉川 克之, 森永 正彦, 湯川 夏夫, 足立 裕彦1990 年 54 巻 5 号 p. 568-574
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーIn order to understand alloying effects on the corrosion of titanium, polarization curves were measured at 343 K in 10 mass%H2SO4 solution for various Ti-M binary alloys (M=Al, Nb, Ta, Zr, Hf, Fe, V, Cr and Mo). The results were interpreted in terms of two parameters obtained by the molecular orbital calculation; one is the bond order (Bo) and the other is the metal d-orbital level (Md). Bo is a measure of the strength of covalent bonds between titanium and alloying elements. Md is correlative with the electronegativity of elements.
It was found that alloys containing elements with higher Bo values showed a lower critical anodic current density in the polarization curve and hence higher corrosion resistance. On the other hand, Md appears to be associated with the corrosion potential of alloys. It is likely that both Bo and Md are useful parameters for describing the corrosion of titanium alloys in a reducing atmosphere such as hydrochloric or sulfuric acid.抄録全体を表示PDF形式でダウンロード (675K) -
伊藤 真二, 佐藤 幸一, 高橋 順次, 大河内 春乃1990 年 54 巻 5 号 p. 575-580
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe fundamental parameter (FP)-XRF analysis of ten alloying elements (Al, Ti, Cr, Mn, Fe, Co, Zr, Nb, Mo and W) in nickel-base heat-resisting alloys was performed with the XRF-11 program.
One nickel-base alloy for multi-elements calibration standard was prepared by a vacuum arc melting method. The homogeneity test of alloying elements in the disk standard was performed by spark emission spectrochemical analysis. Consequently, the disk standard could be used for the FP-XRF analysis calibration. The chemical composition of the calibration standard was determined by the wet chemical analyses and inductively coupled phsma atomic emission spectrometry after ion-exchange separation.
The spectral line overlaps were examined. The correction coefficients for the spectral line overlaps, that is, mMn,Cr, mCo,Fe, mNb,Mo and mMo,Zr, were 0.0004, 0.0003, 0.0004 and 0.0030 respectively. The accuracies for the determination of alloying elements with the proposed method obtained from fifteen standard reference materials were almost equal to those obtained by the correction method using theoretical alpha coefficients. The relative standard deviations (RSD) of repetitive seven measurements for the analytical values of the ten alloying elements were within about 1.5% with the exception of those for manganese (Mn; 0.01%, RSD; 6.08%) and tungsten (W; 0.06%, RSD; 6.69%).抄録全体を表示PDF形式でダウンロード (523K) -
高島 和希, 頓田 英機, 清水 勲, 友納 憲昭, 宮本 美智雄1990 年 54 巻 5 号 p. 581-588
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーExplosive compactions of pure electrolytic iron powder have been conducted using a cylindrically axisymmetric direct method. In the explosive compaction, the ratio of explosive mass to powder mass (E⁄M ratio) and the detonation velocity of explosives were changed to investigate their effects on the compactibility. The optimum compacts, where no cracks were included, were obtained at the E⁄M ratio between 2.5 and 3.0 using PAVEX (detonation velocity 2.3 km/s), and the specific density ratio of the optimum compact reached more than 99%. The compacting pressure estimated using the impedance matching method was about 4.5 GPa for the optimum compaction. On the contrary, no optimum compacts were obtained using SEP (detonation velocity 6.97 km/s), because the compacting pressure was changed drastically with the E⁄M ratio from under-compaction to over-compaction. This result indicates that the use of slow detonation velocity explosive was more favorable to obtain a crack-free compact. Although the tensile strength of the as-compacted material was about 40 MPa, it was increased to 300 MPa by post-sintering treatment at 1123 K for 900 s. The mechanical properties of the explosively compacted and sintered material were superior than those of the conventionally sintered material and were comparable to the melted material.抄録全体を表示PDF形式でダウンロード (2439K) -
末吉 秀一, 田中 秀穂, 末永 勝郎, 田中 良平1990 年 54 巻 5 号 p. 589-595
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe machinability of the tri-phase steel in which fine graphite nodules and fine martensite are dispersed in ferrite matrices is studied by comparing with that of the dual phase steel composed of ferrite and marten-site. The results obtained are summarized as follows.
(1) In the case of low speed cutting by the use of high speed steel tool, flank wear for the tri-phase steel is less than that for the dual phase steel because the abrasive wear decreases due to the lubrication effect of graphite nodules and also stable built-up edge formed protects the tool face.
(2) In the case of high speed cutting by the use of sintered carbide tool, the crater wear for the tri-phase steel is larger than that for the dual phase steel, while the former steel is very small in the wear of flank face and edge as compared with the latter steel. As synthesized these results from the standpoint of the performance of sintered carbide tool, the tri-phase steel may be regarded as superior to the dual phase steel.
(3) The tri-phase steel exhibits an excellent chip-disposability because curvatures of the chips formed are small and the graphite nodules promote the crack propagation in the chips.抄録全体を表示PDF形式でダウンロード (1289K) -
能登谷 久公, 山田 茂, 吉川 和男, 高辻 雄三1990 年 54 巻 5 号 p. 596-602
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe effect of tool materials on machinability of commercially pure titanium was discussed to examine the wear resistance and deposits on rake faces of six kinds of tools. It was found that the cutting performance of CBN and SiN tools lost quickly for chipping on the cutting edge. Wear of the carbide and diamond compax tool increased slowly in comparison with the CBN and SiN tools. From EPMA observations of the deposits on the rake faces it was suggested that tool wear was accelated by diffusion and adherence between the work and tool materials.抄録全体を表示PDF形式でダウンロード (2074K) -
西村 睦, 天野 宗幸, 海江田 義也1990 年 54 巻 5 号 p. 603-610
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe combustion synthesis was applied to preparing ZrNi using elemental powder mixtures in a vacuum of 10−4 Pa and at preheating temperatures of 298-673 K. The combustion synthesis at preheating temperatures not exceeding 373 K yielded porous products, whereas the combustion synthesis at the preheating temperature of 673 K yielded an ingot type product. The propagation rate of the combustion wave was 9.9 mm/s, the maximum combustion temperature was 1483 K and the maximum heating rate was 1730 K/s in case of the preheating temperature of 373 K. No change in the oxygen content of the sample was observed before and after the combustion synthesis. Products of the combustion synthesis contained ZrNi, Ni11Zr9 and Zr2Ni in all the conditions investigated. The difference in nickel particle size caused no conspicuous differences in the amount of the phases in products. Conversion ratios of the powder mixtures to ZrNi were approximately 0.75 and 0.88 in the case of preheating temperatures of 373 and 673 K, respectively. It was considered in the combustion synthesis of ZrNi that a zirconium-rich liquid phase which contained 76% of zirconium and a nickel-rich liquid phase which contained 36% of zirconium or more occurred at the initial stage of the process and then the two liquid phases reacted each other to form ZrNi.抄録全体を表示PDF形式でダウンロード (1977K) -
高倉 英樹, 堀部 進1990 年 54 巻 5 号 p. 611-616
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーThe fatigue failure mechanism of ceramic material has been hardly made clear under cyclic loading. In this study, we examine the damage of the surface area in ceramics under local cyclic compressive loading by using the cyclic indentation method (indentation fatigue), and discuss its mechanism. Four kinds of materials (transgranular and intergranular fracture types) were used for the experiment. The indentation fatigue test was carried out by indenting repeatedly onto the same point of the specimen surface by using a Vickers hardness tester. The median/radial crack length, the number of cycles to chipping and the size of the chipping area were measured, and the lateral crack growth rate was computed. The fracture surface in the chipping area was also observed by a scanning electron microscope. The median/radial crack growth was slightly accelerated by cyclic loading in any material. During cyclic indentation, the lateral crack propagated, which resulted in the chipping phenomenon. Such damage accumulation remarkably occurred in the transgranular fracture type material rather than in the intergranular fracture type one. Striations were observed in the chipping area and the striation spacing approximately corresponded to the size of the chipping area divided by the cycles to chipping, i.e., the lateral crack propagation rate. The observed zigzag propagation of the lateral crack is considered to be attributable to the difference between the stress fields under loading and unloading. The reason why the lateral crack growth and the resultant chipping behavior are suppressed in intergranular fracture type materials is most likely that crack branching and microcracking easily occur in those materials so that the stress concentration at the crack tip is relieved.抄録全体を表示PDF形式でダウンロード (848K) -
佐藤 昭規, 昆 謙造, 辻川 茂男, 久松 敬弘1990 年 54 巻 5 号 p. 617-618
発行日: 1990年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (235K)
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