巻号一覧
64 巻, 1 号
選択された号の論文の12件中1～12を表示しています
- |<
- <
- 1
- >
- >|
-
柴田 政勝, 竹元 嘉利2000 年 64 巻 1 号 p. 1-6
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーA6061 aluminium alloy matrix composites reinforced with aluminium borate whiskers were manufactured using squeeze casting. The interface between the whisker and matrix was observed using high resolution electron microscopy. The aluminium borate whisker and magnesium in the A6061 aluminium alloy interacted during casting and the spinel (MgAl2O4) which nucleated at the interface grew during heat treatment. The whisker/spinel interface had coherency, but the whisker/matrix interface had none. Many lattice defects were observed in the spinel, and were probably produced by misfits at the whisker/spinel interface. Multi-slice simulation indicated that stacking faults are one of the defects.抄録全体を表示PDF形式でダウンロード (1473K) -
落合 庄治郎, 藤田 貴之, 田中 基嗣, 北條 正樹, 田中 良平, 宮村 紘, 中山 裕敏, 山本 雅章, 藤倉 正国2000 年 64 巻 1 号 p. 7-14
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーSimulation study of tensile fracture behavior of unidirectional elastic fiber/elastic matrix composite with weak interface was carried out by means of a Monte Carlo method combined with a modified shear lag analysis. With the present method, following features of weakly bonded composites could be expressed. (1) When the fracture strain of matrix is low, the residual stresses (tensile and compressive stresses along fiber axis for matrix and fiber, respectively) enhances fracture of matrix and interfacial debonding during cooling and/or at low applied strains. As a result, the strength of composite is practically given by the strength of the fiber bundle. (2) When the fracture strain of the matrix and frictional shear stress at the debonded interface increases and the residual stresses decrease, the strength of composite increases. (3) Longitudinal cracks arise at the notch tip and grows to the grip-ends. Therefore, the nocthed strength is given by the net stress criterion.抄録全体を表示PDF形式でダウンロード (959K) -
村田 貴広, 佐藤 正則, 深野 善史, 森永 健次2000 年 64 巻 1 号 p. 15-20
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーMetallic copper nanoparticles in phosphate glasses were prepared by melt-quenching and heat treatment method. Morphology of deposition and dispersion of metallic copper nanoparticles in phosphate glass were investigated by UV-Vis absorption and transmission electron microscopy (TEM) measurements. The time-temperature-deposition (TTD) diagram for the glass dispersed with metallic copper nanoparticles was proposed on the basis of the UV-Vis absorption measurement. The TTD diagram shows that the region in which metallic copper nanoparticles are deposited and mono-dispersed is narrow near the crystallization temperature in 50BaO·50P2O5+6Cu2O+6SnO (mol%) glasses. The TEM photograph of heat-treated 50BaO·50P2O5+6Cu2O+6SnO glass indicates that the amount of deposited metallic copper nanoparticles is small and the average diameter of the particles is approximately 20 nm. We obtained a large amount of uniform matallic copper particles dispersed in 50BaO·50P2O5+6Cu2O+6SnO+2Sb2O3 (mol%) glass samples heated below the glass transition temperature. In order to control the deposition and dispersion of metallic copper nanoparticles in the glass, we discussed the deposition and growth mechanisms of metallic copper nanoparticles in 50BaO·50P2O5+6Cu2O+6SnO and 50BaO·50P2O5+6Cu2O+6SnO+2Sb2O3 glasses in terms of the redox reactions between Cu+ ions and reducing oxides, i.e. SnO and Sb2O3.抄録全体を表示PDF形式でダウンロード (597K) -
金 炳男2000 年 64 巻 1 号 p. 21-26
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーThe grain growth behavior in particle-dispersed materials is investigated by using finite element simulation on the interaction between a curved grain boundary and a spherical particle. By varying the radius of the grain boundary curvature and the particle size, quantitative analyses on the relationship between particle dispersion and mean critical grain size, and between particle dispersion and grain growth rate are carried out. The effect of migration velocity of the grain boundary during the interaction is taken into account in the present analyses. The pinning stress by dispersed particles increases with increasing radius of the grain boundary curvature, and the increasing rate is accelerated as the mean critical radius of curvature is approached. The trapping condition of the grain boundary is evaluated for both cases of a single particle and uniformly distributed particles. The critical grain size is proportional to f−2⁄3 for low f and is proportional to f−0.7 for f≈0.1, where f is the volume fraction of particles. The power law for grain growth is obtained in particle-dispersed materials for f≤0.15, and the grain growth exponent is shown to vary with 2+f0.38.抄録全体を表示PDF形式でダウンロード (575K) -
李 景求, 姜 昌汐, 李 道宰2000 年 64 巻 1 号 p. 27-33
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーEffect of coating treatment by metallic Cu and Ni-P on SiC fiber for SiC/Al composite were studied. Ni-P and Cu were deposited on SiC fiber by the electroless plating method. The coating improved wettability of SiC fibers by Al. Coating by Ni-P turned out more effective. The improved wettability seems to be strongly related to the increase in chemical reactivity between the coating layer and Al matrix. The reaction between Al melt and coated metallic film forms in a eutectic melt, which accelerates the break down of Al oxide film and improves wettability.抄録全体を表示PDF形式でダウンロード (1226K) -
佐貫 須美子, 車古 和恵, 長岡 茂, 真嶋 宏2000 年 64 巻 1 号 p. 34-41
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーThe photocatalytic reduction of aqueous Se(VI) solution was studied using two anatase type powders whose specific surface area and particle size were 145 m2/g and 1.0 μm, and 47.6 m2/g and 0.2 μm, respectively, and an HCOOH reductant. The principal reduction products were Se° and H2Se, but Se(IV) was not detected. The reduction rate of Se(VI) is mainly controlled by the amount of Se(VI) adsorbed onto TiO2 powder, as far as the same TiO2 powders were used. When different TiO2 powders were used, the energy conversion ratio of TiO2 plays a more important role in photocatalytic reduction of Se(VI) or Se°. Using a TiO2 catalyst having a high conversion ratio, the time required for the reduction of Se(VI) to Se° and Se° to H2Se were in the ratios of 3:1, as expected theoretically.
Although the reduction rates of Se(VI) can be approximately presumed knowing the information of adsorption amount of Se(VI) onto TiO2 and energy conversion ratios of TiO2, pH of solution, amount of TiO2 and concentrations of Se(VI) and HCOOH were recognized another important factors.抄録全体を表示PDF形式でダウンロード (838K) -
宮野 公樹, 飴山 惠2000 年 64 巻 1 号 p. 42-49
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーIn order to study the interface boundary structure, a three dimensional Near-Coincidence Site Lattice(3D-NCS) analysis based on Coincidence Site Lattice(CSL) theory has been proposed. In this method, coincidence atoms are calculated by a computer based, atomic matching procedure. To examine the validity of the 3-D NCS analysis, the comparison between this method with the O-lattice theory was made for the preferred orientation relationships in BCC/FCC system. A good correspondence is obtained. As for interface boundary structure, the 3D-NCS analysis is compared with the experimental results obtained by HRTEM observation of an (α+β) two phase titanium alloy. The NCS analysis is able to predict well the α/β interface boundary structure observed experimentally. Therefore, it is suggested that the 3D-NCS analysis is a useful method to predict the structure of interface boundary.抄録全体を表示PDF形式でダウンロード (1042K) -
美野 和明, 福岡 千枝, 吉澤 廣喜2000 年 64 巻 1 号 p. 50-55
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーWith the aim of measuring local strain distribution using electron back-scattered diffraction (EBSD), the evolution of intragranular misorientation during tensile and creep deformations was studied. Test materials include a low-alloyed Cr-Mo steel, Type 304 stainless steel, Ni-based superalloy and pure iron, which were deformed up to 6 pct strain. Although all of the test materials were annealed, misorientations of 0.4 to 0.5 degrees were measured prior to deformation. Misorientation angles subtracted by these initial values linearly increase with plastic strain. The slope was shown to be independent of the kinds of test materials, deformation temperatures and strain rates. The ratios of misorientation angle to strain for the crept Cr-Mo steel with a ferrite-lath structure and aluminum deformed at elevated temperature, calculated from the published works, were shown to lie on the extrapolated line of the present study. TEM observations showed various deformation structures. Slip lines with 0.5 to 1 μm intervals were observed in INCO718, while a tangled dislocation structure was observed in SUS304. Dislocation tangling has developed to a preform of cellular structures in the pure iron strained to 3pct. Dislocations pinned by carbides sparsely distributed in the crept Cr-Mo steel. It was concluded from these observations that intragranular misorientation develops by local rotation of crystal orientations without forming cellular dislocation or subgrain structures.抄録全体を表示PDF形式でダウンロード (1355K) -
進藤 裕英, 真野 恭規, 堀口 勝三, 周郷 智2000 年 64 巻 1 号 p. 56-61
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーThe use of the notch tensile test to estimate the elastic-plastic fracture toughness (JIC) of structural alloys and weldments for superconducting magnets in fusion energy systems was studied. Notch tensile tests were performed with small round bar specimens containing an electro discharge machined (EDM) notch at liquid helium temperature (4 K) using crosshead rates of 3.3×10−3 and 20 mm/s. Notch tensile test specimens were 5 mm in diameter with a 30-mm reduced section. In the mid section of the specimen a 1 mm deep EDM notch of 0.2 mm width was machined around the girth, thus maintaining a starting diameter of 3 mm. Correlations between notch tensile strength, failuar energy absorption, and JIC were assessed. A finite element analysis was also performed to compute directly the J-values. Comparisons of the predicted JIC with results obtained from conventional JIS Z 2284 standard tests were made.抄録全体を表示PDF形式でダウンロード (682K) -
佐藤 守夫, 木村 隆, 澤口 孝宏, 石田 章2000 年 64 巻 1 号 p. 62-66
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーTi-rich Ti-Ni thin films of Ti-45.2, 46.1, 47.0, 47.9, 48.5 at%Ni were prepared by sputtering. The sputter-deposited thin films were annealed at 773, 823 and 873 K for 1 h. Transmission electron microscopy revealed that Ti-45.2 at%Ni thin films contain randomly oriented Ti2Ni particles, while the other films contain Ti2Ni precipitates with the same orientation as that of TiNi matrix. In addition to these Ti2Ni precipitates, GP zones were also observed in Ti-47.9 and 48.5 at%Ni thin films annealed at 773 K for 1 h. The shape memory behavior of the annealed Ti-Ni thin films was investigated with a thermomechanical tester. It was found that martensitic transformation temperature decreases with increasing Ti content and decreasing annealing temperature. However, thin films containing GP zones show low transformation temperatures despite of low Ti content. On the other hand, R-phase transformation temperature was not found to be sensitive to film composition, except for thin films with GP zones, which show low R-phase transformation temperatures as well as low martensitic transformation temperatures. Critical stress for slip deformation was found to increase with increasing Ti content and decreasing annealing temperature. GP zones were helpful in increasing the critical stress of Ti-47.9 and 48.5 at%Ni thin films. Finally, recoverable strain was found to increase with decreasing Ti content and annealing temperature. Especially, the thin films containing GP zones showed large recoverable strains.抄録全体を表示PDF形式でダウンロード (832K) -
渡辺 徹, 南 修介2000 年 64 巻 1 号 p. 67-76
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーIn this investigation, the surface morphology and crystallographic orientation of an electroplated zinc film is studied in regard to changes in plating conditions which include changes plating solution (ZnSO4 bath, ZnCl2 bath, and a mixed bath of these chemicals, as well as a Zn(CH3COO)2 bath and Zn(NO3)2 bath), kinds of substrate material (copper single crystal, and amorphous metal), thickness of the plating film, current density, pH of plating solution and additives. The electroplated zinc film has crystallographic coherency with a single copper crystal. On the amorphous metal substrate the initial zinc film is formed with an aggregation of small zinc crystals. The surface of the electroplated zinc film has a typical morphology depending on the kind of plating solution used. Generally, the surface roughness of the film increases with increasing of film thickness, and the morphology and roughness of the zinc film remains independent of changes in pH and plating temperature. The preferred crystallographic orientation of the film is generally 002, which is also independent of change in pH and plating temperature. The addition of p-cresolsulfonic acid in the bath largely changes the surface morphology and the preferred orientation, while addition of citric acid monohydrate in the bath changes the preferred orientation, but does not change the surface morphology. The preferred orientation of the electroplated zinc film is independent of surface morphology.抄録全体を表示PDF形式でダウンロード (2097K) -
山下 正人, 三澤 俊平, Townsend H. E., Cook D. C.2000 年 64 巻 1 号 p. 77-78
発行日: 2000年
公開日: 2008/04/24
ジャーナル フリーWe have proposed determination procedure of the relative amounts of rust constituents of steel. Mössbauer spectroscopy provides the relative amounts of crystalline rust constituents including ultra-fine crystals. A quantitative analysis of ultra-fine crystals is possible with the resolution of several percent by comparing the Mössbauer results with the relative amounts of rust constituents determined by X-ray diffraction spectroscopy.抄録全体を表示PDF形式でダウンロード (234K)
- |<
- <
- 1
- >
- >|