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DIFFUSION BONDING OF SUPERPLASTIC AI ALLOY LC4

HUANG Yan , MA Longxiang Northeast Universtity of Technology , Shenyang , China lecturer , Department of Metalforming , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

Diffusion bonding of supcrplastic Al alloy LC4,with prior surface treatment of organic solution protecting coating after electroplishing and stainless steel wool brushing,was performed by Gleeble test machine under conditions ranged 490—530 ℃,1.0—3.0 MPa. 30—180 min and vacuum of 1.0×10~(-3) Pa.The joints were examined to have similar strength and microstructure to the base metal Discussion was made on the effect of superplastic treatment on bonding.The micromechanism for diffusion bonding of super- plastic metal was suggested as the migration of original bond interfaces caused by atomic diffusion and grain growth. Experimental results for the alloy as quench-aged state were presented to compare with the superplastic one.

关键词: superplasticity , null , null , null

High-Temperature Oxidation Resistance of Austenitic Stainless Steel Cr18Ni11Cu3Al3MnNb

LI Dong-sheng , DAI Qi-xun , CHENG Xiao-nong , WANG Rong-rong , HUANG Yan

钢铁研究学报(英文版)

The kinetic curve of the high-temperature oxidation of austenitic stainless steel Cr18Ni11Cu3Al3MnNb at different temperatures was measured by weighting method. It is showed that the oxidation curves at 700 and 800 ℃ followed the parabolic law, and the steel presented an excellent anti-oxidation. The surface morphology and structure of the oxide film were studied by scanning electron microscopy and X-ray diffraction methods. A dense oxide film was attained at 700 and 800 ℃, mainly composed of the hexagonal Al2O3, Fe2O3, and a small amount oxide of Cr at 700 ℃. At 900 ℃ the oxide film started to delaminate, and was composed of (Cr,Fe)2O3 and the spinel CuCrMnO4 and Fe(Cr,Al)2O4.

关键词: austenitic stainless steel , high-temperature oxidation , oxidation scale , cyclic oxidation , spinel

Cu-Zr/ZrN薄膜体系的电阻率和纳米压入研究

白宣羽 , 汪渊 , 徐可为

稀有金属材料与工程

采用磁控溅射方法在Si(111)基片上沉积Cu-Zr/ZrN薄膜体系作为扩散阻挡层.通过比较Cu-Zr/ZrN薄膜体系和三元非晶(Mo,Ta,W)-Si-N的电阻率,同时比较Cu-Zr/ZrN薄膜体系和Ta,YaN的硬度,说明作为扩散阻挡层的材料的选取,应从整体性能上考虑,而不能仅仅考虑热稳定性等单一指标.

关键词: 非晶 , 电阻率 , 纳米压入 , 硬度

密相气力输送颗粒静电波动信号多尺度分析

许传龙 , 王式民

工程热物理学报

在加压密相气力输送实验装置上获得了不同操作条件下煤粉颗粒静电波动信号,并用Hilbert-Huang变换、功率谱进行分析.结果表明:随着表观速度的增加,静电波动信号主峰值的频率增大;静电波动信号希尔伯特-黄变换(Hilbert-Huang)揭示了气固两相流静电信号的非线性和非平稳特征,随气固两相流颗粒相浓度降低和颗粒及表观速度增加,静电波动信号特征尺度由高尺度(低频)向低尺度(高频)转移.多尺度分析有助于认识气固两相流动形态及其转变规律.

关键词: 颗粒静电 , 静电传感器 , 气-固两相流 , Hilbert-Huang变换

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....

关键词:

Shock compression of monocrystalline copper: Experiments, characterization, and analysis

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Monocrystalline copper samples with [001] and [221] orientations were subjected to shock/recovery experiments at 30 and 57 GPa and 90 K. The slip system activity and the microstructural evolution were investigated. Different defect structures, including dislocations, stacking faults, twins, microbands, and recrystallized grains were observed in the specimens. The residual microstructures were dependent on crystalline orientation and pressure. The differences with crystalline orientations are most likely due to different resolved shear stresses on specific crystalline planes. The geometric relationships between the shock propagation direction and crystalline orientation are presented under uniaxial strain. It is shown that the [2 2 11 orientation, by virtue of having fewer highly activated slip systems, exhibits greater concentration of deformation with more intense shear on the primary system. This, in turn leads to greater local temperature rise and full recrystallization, in spite of the thermodynamic residual temperature of similar to 500 K and rapid cooling (within 20 s) to ambient temperature. The profuse observation of microbands is interpreted in terms of the mechanism proposed by Huang and Gray [J.C. Huang, G.T. Gray III, Acta Metallurgica 37 (1989) 3335-3347]. (C) 2009 Elsevier B.V. All rights reserved.

关键词: Shock compression;Shock loading;Slip bands;Microtwins;Microbands;strain rate history;single-crystals;grain-size;constitutive;description;plastic-deformation;mechanical response;deformed metals;loaded nickel;substructure;recrystallization

Studies of the g factors and the local structure for Ni3+in LaAl0.9Ni0.1O3, La0.75Y0.25Al0.99Ni0.01O3 and YAl0.9Ni0.1O3

Radiation Effects and Defects in Solids

The electron paramagnetic resonance g factors and the local structure for Ni3+ in LaAl0.9Ni0.1O3 (LAN), La0.75Y0.25Al0.99Ni0.01O3 (LYAN) and YAl0.9Ni0.1O3 (YAN) are theoretically studied from the perturbation formulas of the g factors for a 3d7 ion of low spin (S = 1/2) in tetragonally elongated octahedra. In these formulas, the contributions to the g factors from the tetragonal distortion, characterized by the tetragonal field parameters Ds and Dt are taken into account. According to the calculations, the ligand octahedra around Ni3+ are suggested to suffer 2% relative elongation along the [001] (or C4) axis due to the Jahn-Teller effect.

关键词: defect structures;electron paramagnetic resonance;crystal-fields and;spin Hamiltonians;Ni3+;LaAlO3;LaYAlO3;YAlO3;atomic screening constants;optical-spectra;paramagnetic-resonance;superconducting tapes;lattice-distortions;superposition model;scf;functions;cr3+ ions;crystals;epr

非微扰QCD和核遮蔽效应对K因子的影响

智海素 , 侯召宇

原子核物理评论 doi:10.3969/j.issn.1007-4627.2006.01.002

考虑非微扰量子色动力学物理真空夸克凝聚效应,计算了碳核与碳核在质心系能量分别为630和200 GeV时碰撞Drell-Yan过程的K因子,以及加入核遮蔽因子后非微扰效应对K因子的影响,并把计算结果与没有考虑夸克凝聚非微扰效应的K值进行了对比.结果表明,非微扰效应和核遮蔽效应对K因子影响很小.

关键词: K因子 , Drell-Yan过程 , 夸克凝聚 , 非微扰量子色动力学 , 核遮蔽效应

Mean-field theory for ferroelectricity in Ca(3)CoMnO(6)

Physical Review B

An elastic Ising model for CoMnO(6) chain is proposed to explain the ferroelectricity induced by collinear magnetic order in Ca(3)CoMnO(6), and then a mean-field theory with interchain spin interactions based on this model is developed. With inclusion of the dynamics of polarization domains at finite temperature, we address the rationality of our theory by the good agreement of the calculated electric polarization and dielectric susceptibility with the reported data on Ca(3)Co(2-x)Mn(x)O(6) (x approximate to 0.96) [Y. J. Choi, H. T. Yi, S. Lee, Q. Huang, V. Kiryukhin, and S.-W. Cheong, Phys. Rev. Lett. 100, 047601 (2008)], a typical diatomic Ising spin chain system, while the predicted magnetic susceptibility shows some difference from experiment, the reason of which is discussed.

关键词: calcium compounds;cobalt compounds;dielectric polarisation;ferroelectricity;Ising model;magnetic susceptibility;multiferroics;optical susceptibility;one-dimensional oxides;magnetic-properties;multiferroics;ca3co1+xmn1-xo6

Lu-induced orthorhombic phase in polycrystalline La0.7Sr0.3MnO3

Physica B-Condensed Matter

Polycrystalline La0.5Lu0.2Sr0.3MnO3 samples prepared by thermal decomposition are investigated by means of electron diffraction and high-resolution transmission electron microscopy. Besides rhombohedral La0.7Sr0.3MnO3 phase (R-phase) and hexagonal LuMnO3 phase (H-phase) reported by Huang, unexpectedly, an orthorhombic lattice (O-phase) with space group Pnma is observed in the interior of R-phase grain. The lattice parameters of the orthorhombic unit cell are a(o) = 5.44 angstrom, b(o) = 7.65 angstrom and c(o) = 5.48 angstrom The formation of O-phase results from a(-)b(+)a(-) type orthorhombic distortion of MnO6 octahedra induced by partial substitution of Lu3+ for La3+. Meanwhile, based on image simulation of the interface between R and O-phases, the atomic bonding on the interface is particularly discussed. (c) 2005 Elsevier B.V. All rights reserved.

关键词: orthorhombic lattice;octahedral;substitution;atomic bonding;la0.7-xluxsr0.3mno3 perovskites;transport-properties;magnetoresistance;films

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