P. R. Ding
,
D. Y. Ju
,
T. Lnouc and E. de Vries( 1) MSC Japan Ltd.
,
Osaka
,
Japan 2) Saitama Institute of Technology
,
Saitama
,
Japan 3) Kyoto Universily
,
Kyoto
,
Japan 4) MacNeal - Schwendler (E. D. C. ) B. V.
,
Gouda
,
The Netherlands)
金属学报(英文版)
A method to simulate processes of forging and subsequent heat treatment of an axial symmetric rod is formulated in eulerian description and the feasibility is investigated. This method uses finite volume mushes for troching material deformation and an automatically refined facet surface to accurately trace the free surface of the deforming material.In the method,the deforming work piece flows through fixed finite volume meshes using eulerian formulation to describe the conservation laws,Fixed finite volume meshing is particularly suitable for large three-dimensional deformation such as forging because remeshing techniques are not required, which are commonly considered to be the main bottelencek in the ssimulations of large defromation by using the finite element method,By means of this finite volume method, an approach has been developed in the framework of "metallo-thermo-mechanics" to simulate metallic structure, temperature and stress/strain coupled in the heat treatment process.In a first step of simulation, the heat treatment solver is limited in small deformation hypothesis,and un- coupled with forging. The material is considered as elastic-plastic and takes into account of strain, strain rate and temperature effects on the yield stress.Heat generation due to deformation,heat con- duction and thermal stress are considered.Temperature - dependent phase transformation,stress-in- duced phase transformation,latent heat,transformation stress and strain are included.These ap- proaches are implemented into the commerical commercial computer program MSC/SuperForge and a verification example with experimental date is given as comparison.
关键词:
finite volume method
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null
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null
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null
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null
K. Mii (Sumitomo Metal Industries
,
Ltd.
,
1-t-3 Otemachi
,
Tokyo 100
,
Japan)M Amano (National Research Institute for Metals
,
1-2-1 Sengen
,
Tsukuba 305
,
Japan)
金属学报(英文版)
The R & D of hydrogen absorbing alloys in Japan started in the early 1970s.Many alloys such as TiMm1.5 based alloys, Fe-Ti-O alloys (e.g. FeTi1.15 O0.024) andthe(mischmetal)Ni5 based alloys (e.g. MmNi4.5 Cr0.46 Mn0.04) were developed by the early 1980s. The application of these alloys to hydrogen storage, heat storage, heat pump, hydrogen purification and motor vehicles has been tried in many iaboratories,and the various techniques for using hydrogen absorbing alloys have been developed.The standarkization of evaluation methods for hydrogen absorbing alloys has been promoted by the Ministry of International Trade and Industry (MITI), and four of them were established as Japanese Industrial Standard (JIS).Alloys for Ni-Metal Hydride batteries have been extensively investigated since 1987in Japun. Mm-Ni-Co-Al-Mn alloys (e.g. MmNi3.55 Co0.75Al0.9Mn0.4) have been devel-oped and commereialized since 1990. The amount of production of small-size Ni-MH batteries in 1995 was about three hundred milliion in number and about one hundred billion yen. The R & D for higher enerpy-density Ni-MH batteries is intensively in progress.MITI and STA (Science and Technology Agency) have promoted the R & D of hydro-gen absorbing alloys in Japan by carrying out the national projects such as Sunshine Program (MITI: 1974-1993) and Utilization of Wind Engeray (STA 1980-1985). The New Sunshine Program (MITI 1993-2020) have started in 1993. This program con-tains the application of hydrogen absorbing alloys to Economical- Enerpy- City System and to We-NET (International Clean Energy System of Technology Utilizing Hydro-gen: World Energy Network.
关键词:
hydrogen absorbing alloy
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null
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null
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null
Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers
The temperature, frequency, and voltage dependences of the dielectric properties of 0.93Pb(Fe(1/2)Nb(1/2))O(3)-0.07PbTiO(3) single crystals were investigated in the temperature range of 100-300 K. An anisotropic colossal dielectric response was observed when the probe of the AC field was along the [100] and [111] directions. One relaxation was detected in the [100] direction, while two relaxations were detected in the [111] direction. The activation energies of the relaxations are in the range of 0.155-0.190 eV, indicating that the relaxations are probably caused by 3d electrons hopping between Fe(2+) and Fe(3+). The origin of the anisotropic colossal dielectric response can be explained by a "two-hopping path'' model. (C) 2011 The Japan Society of Applied Physics
关键词:
ceramics
Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers
The structures and dielectric properties of Pb(Fe1/2Nb1/2)(1-x)TixO3 (PFNT, x = 0.07 and 0.48) single crystals were investigated using a combination of temperature-dependent dielectric, X-ray diffraction (XRD), Raman, and X-ray absorption fine structure (XAFS) spectra. Detailed structure analyses reveal that the crystal structure of PFNT (x = 0.48) is single-phase tetragonal perovskite, whereas that of PFNT (x = 0.07) is a mixture of rhombohedral and tetragonal phases. The structural differences are found to have significant connections with the dielectric properties in the temperature range of 90-300 K. Both samples exhibit a frequency-dependent dielectric anomaly, arising primarily from the 3d electrons hopping between Fe2+ and Fe3+. The second dielectric anomaly, which is a weak frequency dispersion and observable only for PFNT (x = 0.07), was probably caused by a dipole glass behavior near the morphotropic phase boundary. (C) 2012 The Japan Society of Applied Physics
关键词:
iron;fe;ceramics;region;xanes
Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers
Single-walled carbon nanotube:poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) hybrid film (SWCNT:PEDOT/PSS) hybrid conducting film was obtained by using spray-coating technique, based on which a white flexible organic light emitting diode (FOLED) was fabricated with the structure of SWCNT:PEDOT/PSS/N,N-diphenyl-N,N-bis(1-napthyl)-1,1-biphenyl-4,4-diamine/5,6,11,12-tetraphenylnaphthacene:4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl/4,7-diphenyl-1,1'-phenanthroline/LiF/Al. The hybrid film exhibited superior surface morphology, electrical conductivity to the pure SWCNT network. The as-fabricated FOLED showed a stable white emission that is close to the equi-energy white point upon bending, and the light-emitting efficiency of the device was significantly improved by using the hybrid film as anode. The hybrid film holds promise for application in flexible lighting and display. (C) 2012 The Japan Society of Applied Physics
关键词:
solar-cells;electrodes;nanotubes;flexibility;pedot/pss
彭夷安
,
曹小妹
,
雷春华
,
刘利民
,
李其华
,
廉世勋
中国稀土学报
研究了Ba3La(BO3)3 基质中Dy3+ 的光致发光特性; 探讨了RE3+的电荷半径比(z/r)和Ce3+, Dy3+ 含量对Dy3+ 发光强度及发光颜色的影响; 分析了Ba3La(BO3)3 中Ce3+ 对Dy3+ 发光的敏化作用; 确定了Dy3+ 的 4F9/2→6H15/2及4F9/2→6H13/2跃迁发射的浓度猝灭机制均为电偶极-电四极相互作用.
关键词:
发光学
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Dy3+
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Ba3La(BO3)3
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光致发光
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浓度猝灭
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稀土
Lihui ZHU
,
Xueming MA
材料科学技术（英文）
2.25Cr-1.6W-V-Nb developed in Japan, is a low alloy heat resistant steel with good comprehensive properties. Influence of long term creep at elevated temperature on the structure of 2.25Cr-1.6W-V-Nb steel was studied in this paper, and the micromechanism of creep strength degradation was elucidated, too. Both TEM observation and thermodynamic calculation reveal that during creep the transformation occurs from M7C3 and M23C6 to M6C, which can be cavity nucleation sites. Besides, creep at 600℃ also leads to the decrease of dislocation density, the coarsening and coalescence of M23C6, the nucleation of cavities and development of cracks. The strength decrease of 2.25Cr-1.6W-V-Nb steel after long term creep is related to the decrease of dislocation hardening, precipitation hardening, solution hardening, the nucleation of cavities and development of cracks.
关键词:
Heat resistant steel
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null
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null
Journal of Luminescence
Ln(3+) (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Er)-doped Y3GaO6 compounds were prepared by solid-state reaction, and their optical spectra such as absorption, photoluminescence, excitation and time-resolved spectra have been measured for Ln Nd, Sm, Dy, Ho, Er. X-ray powder diffraction shows that the lattice parameters of the compounds (Y(0.96)Ln(0.04))(3)GaO6 decrease with the decrease of the radii of trivalent Ln(3+) ions, indicating that Ln(3+) ions have substituted for y(3+) ions in the lattice. Optical spectra show that there are obvious absorptions at ultraviolet to visible region. The strong emissions in visible and infra-red region show that Y3GaO6 is a suitable host for rare-earth-doped laser crystal and phosphor materials. (C) 2004 Elsevier B.V. All rights reserved.
关键词:
crystal-field;absorption-spectra;luminescence;y3ga5o12;glasses;garnet;y2o3;ions;laf3;tb3
Journal of Alloys and Compounds
The subsolidus phase relations in the ZnO-MoO3-B2O3, ZnO-MoO3-WO3 and ZnO-WO3-B2O3 ternary systems have been investigated by the means of X-ray powder diffraction (XRD). There is no ternary compound in all the systems. There are five binary compounds and five tie lines in the ZnO-MoO3-B2O3 system. This system can be divided into six 3-phase regions. There are three binary compounds and three tie lines in the ZnO-MoO3-WO3 system. This system can be divided into four 3-phase regions. There are four binary compounds and four tie lines in the ZnO-WO3-B2O3 system. This system can be divided into five 3-phase regions. The possible component regions for ZnO single crystal flux growth were discussed. The phase diagram of Zn3B2O6-ZnWO4 pseudo-binary system has been constructed, and the result reveals this system is eutectic system. The eutectic temperature is 1007 degrees C and eutectic point component is 70 mol% Zn3B2O6. (c) 2007 Elsevier B.V. All rights reserved.
关键词:
ZnO-MoO3-B2O3;ZnO-MoO3-WO3;ZnO-WO3-B2O3;Zn3B2O6-ZnWO4;phase relation;zno single-crystals;zinc oxide;growth;moo3-wo3
