Precipitate Structure in an Alumina Dispersion-Strengthened Copper Base Composite Layer

2010 ◽  
Vol 152-153 ◽  
pp. 634-638
Author(s):  
Bao Hong Tian ◽  
Xiao Hong Chen ◽  
Yi Zhang ◽  
Yong Liu
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Composite Layer ◽  
Lattice Parameter ◽  
Interface Structure ◽  
Parameter Mismatch ◽  
Direction Parallel ◽  
Transmission Electron ◽  
The Matrix ◽  
Α Al2o3

A dilute copper alloy of Cu-0.45wt%Al -0.066wt %Y was selected to fabricate nanometer size Al2O3 particles dispersion-hardened composite layer by using aluminizing-internal oxidation technique. The structure and size of the precipitate, interface structure, lattice parameter mismatch and morphology were investigated by means of high resolution transmission electron microscope, analytical transmission electron microscope and image processing by VEC software. Results show that two different size and structure nano-alumina precipitate were identified as α-Al2O3 and γ-Al2O3 respectively during different processing. The precipitates possess semi-coherence or coherence interface structure to matrix with typical loop-loop contrast. The cubic γ-Al2O3 precipitate in certain crystal plane and direction parallel to the matrix。

Measurement of lattice parameter at the nanometer scale using convergent-beam microdiffraction from a thermal emission source

1993 ◽  
Vol 51 ◽  
pp. 690-691
Author(s):  
W. T. Pike
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Thermal Emission ◽  
Lattice Parameter ◽  
Scanning Transmission Electron Microscope ◽  
Emission Source ◽  
Device Structure ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Convergent Beam

With the advent of crystal growth techniques which enable device structure control at the atomic level has arrived a need to determine the crystal structure at a commensurate scale. In particular, in epitaxial lattice mismatched multilayers, it is of prime importance to know the lattice parameter, and hence strain, in individual layers in order to explain the novel electronic behavior of such structures. In this work higher order Laue zone (holz) lines in the convergent beam microdiffraction patterns from a thermal emission transmission electron microscope (TEM) have been used to measure lattice parameters to an accuracy of a few parts in a thousand from nanometer areas of material.Although the use of CBM to measure strain using a dedicated field emission scanning transmission electron microscope has already been demonstrated, the recording of the diffraction pattern at the required resolution involves specialized instrumentation. In this work, a Topcon 002B TEM with a thermal emission source with condenser-objective (CO) electron optics is used.

Transmission Electron Microscope Specimen Preparation of Metal Matrix Composites Using the Focused Ion Beam Miller

2000 ◽  
Vol 6 (5) ◽  
pp. 452-462 ◽  
Author(s):  
Julie M. Cairney ◽  
Robert D. Smith ◽  
Paul R. Munroe
Keyword(s):  
Electron Microscope ◽  
Metal Matrix Composites ◽  
Transmission Electron Microscope ◽  
Metal Matrix ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Matrix Composites ◽  
Transmission Electron ◽  
The Matrix ◽  
Ceramic Reinforcement

AbstractTransmission electron microscope samples of two types of metal matrix composites were prepared using both traditional thinning methods and the more novel focused ion beam miller. Electropolishing methods were able to produce, very rapidly, thin foils where the matrix was electron transparent, but the ceramic reinforcement particles remained unthinned. Thus, it was not possible in these foils to study either the matrix-reinforcement interface or the microstructure of the reinforcement particles themselves. In contrast, both phases in the composites prepared using the focused ion beam miller thinned uniformly. The interfaces in these materials were clearly visible and the ceramic reinforcement was electron transparent. However, microstructural artifacts associated with ion beam damage were also observed. The extent of these artifacts and methods of minimizing their effect were dependent on both the materials and the milling conditions used.

Interface Structure and Layer Synthesis Modes in Mesotaxial Si/CoSi2/Si Structures

1990 ◽  
Vol 183 ◽  
Author(s):  
R. Hull ◽  
Y. F. Hsieh ◽  
K. T. Short ◽  
A. E. White ◽  
D. Cherns
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Lattice Parameter ◽  
Interface Structure ◽  
Interfacial Structure ◽  
Parameter Mismatch ◽  
Alternative Method ◽  
Transmission Electron

AbstractWe report observations of interfacial structure and consequences for layer synthesis modes in mesotaxial Si/CoSi2/Si structures, as deduced from high resolution transmission electron microscopy (HRTEM). It is argued that relative crystal misalignments arising from the lattice parameter mismatch between the Si and CoSi2 may render classic rigid shift measurements of interfacial structure inaccurate. An alternative method for determining interfacial structure at threedimensional precipitates by analyzing crystal stacking sequences is demonstrated.

Electron Image Series Reconstruction of Twin Interfaces in InP Superlattice Nanowires

2011 ◽  
Vol 17 (5) ◽  
pp. 752-758 ◽  
Author(s):  
Martin Ek ◽  
Magnus T. Borgström ◽  
Lisa S. Karlsson ◽  
Crispin J.D. Hetherington ◽  
L. Reine Wallenberg
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Transmission Electron Microscope ◽  
Interface Structure ◽  
Twin Structure ◽  
Twin Interface ◽  
Transmission Electron ◽  
Electron Image ◽  
Model Structures ◽  
Aberration Corrected

AbstractThe twin interface structure in twinning superlattice InP nanowires with zincblende structure has been investigated using electron exit wavefunction restoration from focal series images recorded on an aberration-corrected transmission electron microscope. By comparing the exit wavefunction phase with simulations from model structures, it was possible to determine the twin structure to be the ortho type with preserved In-P bonding order across the interface. The bending of the thin nanowires away from the intended ⟨110⟩ axis could be estimated locally from the calculated diffraction pattern, and this parameter was successfully taken into account in the simulations.

The Microscopic Study of Y-Ba-Cu-O Compound

1987 ◽  
Vol 99 ◽  
Author(s):  
W. T. Lin ◽  
H. C. Chu ◽  
B. H. Chen ◽  
Y. H. Chang ◽  
T. S. Chin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Orientation Relationship ◽  
Microscopic Study ◽  
Transmission Electron Microscope ◽  
Air Cooling ◽  
Twin Boundaries ◽  
Major Phase ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTThe microstructure of Y-Ba-Cu-O compound, sintered at 950°C for 16h, was examined by using transmission electron microscope(TEM). For the furnace cooling sample, two variants of–orthorhombic YBa2-Cu3O7−x (O-Y123) twins, grown on (110) and (110) planes, respectively, are crystallographically related to the matrix and produce a Widmanstatten morphology. The orientation relationship between the lath twin and the matrix is (001)T//(001) and [100]T//[010]M. The O-Y123 compound is unstable under tne electron irradition. Twin boundaries are identified as S-boundaries. The minor phases as Y2BaCuO5 (Y211) and BaCuO2 were also observed. For the air cooling sample, no superconductivity above 77K was found. The major phase is tetragonal Y123 (T-Y123), while small amount of 0-Y123 is also existent.

Interface structure of GaN on sapphire (0001) studied by transmission electron microscope

1998 ◽  
Vol 189-190 ◽  
pp. 295-300 ◽  
Author(s):  
Tsuyoshi Onitsuka ◽  
Takahiro Maruyama ◽  
Katsuhiro Akimoto ◽  
Yoshio Bando
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Interface Structure ◽  
Transmission Electron

Effect of Heat Treatment on the Microstructure of Cu-Cr-Zr Alloy

2017 ◽  
Vol 727 ◽  
pp. 166-170 ◽  
Author(s):  
Li Jun Peng ◽  
Hao Feng Xie ◽  
Gao Lei Xu ◽  
Guo Jie Huang ◽  
Zhen Yang
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Homogenization Temperature ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Transmission Electron ◽  
The Matrix ◽  
Zr Alloy

Effect of Heat treatments on microstructure in a Cu-0.71Cr-0.12Zr alloy (in wt.%) have been investigated. The microstructures are analyzed by optical microscope, scanning electron microscope, transmission electron microscope and high-resolution transmission electron microscope after each step of heat treatments. The results show that the as-cast microstructure of Cu-Cr-Zr alloy is Cu matrix, Cr dendrite and eutectic structure which is composed of Cu and Cu5Zr phase with a fine lamellar structure. By increasing the homogenization temperature or prolonging the holding time, the eutectic structure is dissolved into the matrix gradually and the volume fraction of the Cr phases is obviously reduced. The precipitation of Cr phase prevents from Zr-rich phases dissolving in the matrix. And the proper homogenizing process is 900°C×12 h. When the alloy aged at 450°C for 24 h, the crystallography of Cr precipitates and the orientation relationship between Cr precipitates and Cu matrix is bcc structure and KS-OR, respectively. The disk-shaped precipitate is identified as Cu5Zr phase and their habit plane is parallel to {111}Cu plane.

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