R.M. Wang
,
C.Z. Li
,
S. W. Zhang and M.G.Yan(1)Institute of Aeronautical Materials
,
Beijing 100095
,
China 2)Laboratory of Atomic Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China 3)Beijing Laboratory of Electron Microscopy
,
Chinese Academy of Sciences
,
Beijing 100080
,
China Manuscript received 26 August 1996)
金属学报(英文版)
The microstructures of the grain boundary phases in Fe-Ni-Co-Nb-Ti superalloy have been studied by high resolution electron microscopy (HREM).Besides the Laves phase,three other grain boundary phases have been found and analyzed. The ε phase particles are needle-like with some stacking faults along the(0001) direction. The dominant phase at the grain boundaries is the orthorhombic phase that is also rod-like. High reselution image also confirms the existence of the triclinic phase at the grain boundaries that is irregular and scarce.
关键词:
:high resolution electron microscopy
,
null
,
null
WANG Haifeng
,
ZHANG Chunxia
,
QI Yuanhong
钢铁研究学报(英文版)
China is short of water seriously. But granulation of blast furnace slag (BFS) with water has many disadvantages, such as high water consumption and difficulty in heat recycling. So developing a new dry granulation technique to treat BFS is very important. The applicability of BFS directly depends on the content of non-crystalline solids in the slag after treatment. So it is of theoretical and practical significance to analyze the content of non-crystalline solids in the slag quantitatively and simply. Metallographical test is mainly adopted to quantify the non-crystalline in BFS now with the shortages such as making sample complexly, determining difficultly and personally. For the diffraction intensity of non-crystalline is proportionate to the content of non-crystalline in BFS, X-ray diffraction method was adopted to quantify the non-crystalline and the crystalline solids in BFS. The quantificational coefficient between the crystalline and the non-crystalline solids of BFS is 0.70 whose main composition is: w（CaO）38.2%，w（SiO2）35.7%，w（Al2O3）16.3%，w（MgO）8.3%. The relatively error of using X-ray diffraction instrument to quantitative analyse non-crystalline content of BFS is less than 1%.
关键词:
Blast Furnace Slag;Non-Crystalline;Crystalline;Quantificational Analysis
Acta Materialia
The microstructures of bulk Zr(2)Al(3)C(4) and Zr(3)Al(3)C(5) ceramics have been investigated using transmission electron microscopy and scanning transmission electron microscopy. These two carbides were determined to have a point group 6/mmm and a space group P6(3)/mmc using selected-area electron diffraction and convergent beam electron diffraction. The atomic-scale microstructures of Zr(2)Al(3)C(4) and Zr(3)Al(3)C(5) were investigated through high-resolution imaging and Z-contrast imaging. Furthermore, intergrowth between Zr(2)Al(3)C(4) and Zr(3)Al(3)C(5) was identified. Stacking faults in Zr(3)Al(3)C(5) were found to result from the insertion of an additional Zr-C layer. Cubic ZrC was occasionally identified to be incorporated in elongated Zr3Al3C5 grains. In addition, Al may induce a twinned ZrC structure and lead to the formation of ternary zirconium aluminum carbides. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
TEM;carbides;layered structures;STEM;transmission electron-microscope;mechanical-properties;crystal-structure;ternary-systems;behavior;ti3sic2;al;carbide;ti2alc;phases
Composites Science and Technology
The thermal expansion of the reference sample, pure copper film in the temperature range of - 120 to 200 degrees C was first measured using the newly improved CCD imaging technique for measurement of thermal expansion of thin films. The results showed good accordance with the recommended data given by TPRC (Thermophysical Properties Research Centre, USA) handbook, verifying that the present method is valid for measuring thermal expansion of films. Then, the thermal expansion TE (Delta L/L-0) of silica/polyimide composite films with different SiO2 fractions i.e. 0, 1, 3, 5, 8, 10 and 15 wt% prepared using the sol-gel technique was obtained in the temperature range of - 120 to 200 degrees C using the newly improved CCD method and the differential coefficient thermal expansion (CTE) can be deduced by Delta L/L-0 similar to temperature relation. The CTE Of SiO2/PI Composite films decreased with the increase Of SiO2 content and the decrease of temperature. An empirical equation of CTE of SiO2/PI with SiO2, content has been given in this paper. (C) 2007 Elsevier Ltd. All rights reserved.
关键词:
silica/polyimide composite film;thermal expansion;CCD imaging;technique;low temperature;elevated temperature;mechanical-properties;cryogenic properties;nanocomposite films;polyimide films;low-temperature;silica
Journal of Physics-Condensed Matter
We discuss the interaction between two-level systems and the phonon field in non-crystalline dielectric solids, and we calculate the quantum transition matrix elements of such an interaction. After studying the Boltzmann equation for phonon transport, we obtain the phonon distribution function. From a direct calculation of the heat current, and as a result of obtaining the thermal conductivity of non-crystalline dielectric solids, the T2 relation is obtained.
关键词:
heat
Chinese Physics Letters
We study the crack propagation in layered solids and find that when there exists an easy-fractured layer, the fractal surface becomes more rough, which is characterized by larger fractal dimensions.
关键词:
dimension
Journal of the American Ceramic Society
A HfAlC composite composed of HfAl4C4 and Hf2Al4C5 was successfully synthesized by the hot-pressing method. The atomic-scale microstructure was investigated through high-resolution transmission electron microscopy (TEM) and Z-contrast scanning transmission electron microscopy (STEM) imaging. The TEM observations revealed that the HfAlC grains had elongated morphologies. There was no amorphous phase in the grain boundary. The microstructure of the composite was characterized by the stacking faults resulted from the insertion of (Al4C3) units, which led to the formation of a new phase Hf4Al12C13 and intergrowth structure between HfAl4C4 and Hf2Al4C5. In addition, the antiphase grain boundary in the ternary-layered ceramics was first observed and the formation mechanism was discussed.
关键词:
transmission electron-microscope;theoretical elastic property;crystal-structure;grain-boundaries;ternary ceramics;carbides;oxidation;zr2al3c4;zr3al3c5;antiphase
