High-resolution electron microscopy imaging of a twin-like domain boundary inα′-Ag-Mg alloy

1986 ◽  
Vol 5 (11) ◽  
pp. 1119-1121 ◽  
Author(s):  
J. Mäki
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Domain Boundary ◽  
High Resolution Electron Microscopy ◽  
Mg Alloy ◽  
Microscopy Imaging ◽  
Resolution Electron

Structures of a Stacking Fault and a Rotational Domain Boundary in CVD α-Silicon Nitride

1995 ◽  
Vol 1 (6) ◽  
pp. 263-266
Author(s):  
D.S. Zhou ◽  
T.E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Domain Boundary ◽  
Analytical Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Stacking Fault ◽  
Translational Displacement ◽  
Resolution Electron ◽  
The Difference ◽  
Simulated Images

A 1/2[0001](0001) stacking fault and a planar 60° rotational domain boundary on the (0001) plane in as-grown CVD α-Si3N4 crystals have been characterized by high-resolution electron microscopy and image simulation. As reported previously, two types of coherent boundaries have been observed in this material, namely, stacking faults and rotational domain boundaries. The former involves only a translational displacement, while the latter separates two grains by a 60° rotation in addition to a translation. Inasmuch as the difference resulting from the rotational component can hardly be detected by high-resolution electron microscopy, care must be taken to analyze them first by analytical electron microscopy. In this paper, these two types of boundaries are studied and structural models are constructed that give simulated images in satisfactory agreement with observed images.

Double hexagonal superstructure of Au–Mg alloy containing 20 at.% Mg studied by high-voltage high-resolution electron microscopy

1983 ◽  
Vol 16 (2) ◽  
pp. 233-238 ◽  
Author(s):  
D. Shindo ◽  
K. Haraga ◽  
M. Hirabayashi ◽  
O. Terasaki ◽  
D. Watanabe
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
High Voltage ◽  
High Resolution Electron Microscopy ◽  
Mg Alloy ◽  
Orthorhombic Structure ◽  
Resolution Electron ◽  
The Many ◽  
Imaging Conditions

High-resolution observations of Au–20.2 at.% Mg alloy have been carried out by using a 1 MV electron microscope. The many-beam images with the [001] axial illumination are interpreted in terms of the double hexagonal superstructure of 9a 0−4H type. With the aid of computer simulations by the multislice method, it is revealed that two kinds of interpretable image are obtained for different specimen thicknesses at the optimum defocus. The imaging conditions are discussed in comparison with the orthorhombic structure of the D023 type.

Microstructure of Massively Transformed γ-TiAl Phase Studied by High-Resolution Electron Microscopy

1996 ◽  
Vol 460 ◽  
Author(s):  
E. Abe ◽  
T. Kumagai ◽  
S. Kajiwara ◽  
M. Nakamura
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Domain Wall ◽  
Domain Boundary ◽  
High Resolution Electron Microscopy ◽  
Massive Transformation ◽  
Mirror Plane ◽  
Al Alloy ◽  
Twin Boundaries ◽  
Resolution Electron

ABSTRACTA microstructure of the massively transformed γ-TiAl (γm) phase in a Ti-48at.%Al alloy, which was heat treated in the high-temperature α-Ti (disordered hep) single phase field (1683K), followed by ice water quenching, has been examined using high-resolution electron microscopy. The characteristic features of the microstructure originated from the α→γ massive transformation have been clarified in detail, which are as follows. (1) Extremely thin hep plates (about 0.8–2nm in thickness), which are considered to be a retained α phase, are found to exist in the γm phase. (2) Twin boundaries are found to be not flat interfaces, that is, twin interfaces are not on the exact (111) mirror plane. This situation is attributed to the existence of a number of partial dislocations at the twin boundaries. (3) Antiphase relationship between the regions either side of the thin rotated domain wall [1] is confirmed. The validity of this situation is explained by assuming that the thin rotated domain wall has been grown from a simple antiphase domain boundary. On the basis of these facts, mechanism of the α→γ massive transformation has been discussed.

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