Analysis of grain boundaries in CoCrTa and CoPtCrB HDD media by analytical transmission electron microscopy

2005 ◽  
Vol 54 (1) ◽  
pp. 1-9 ◽  
Author(s):  
K. Shoda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundaries ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

Development of Microstructure in Mechanically Alloyed NiAl

1994 ◽  
Vol 364 ◽  
Author(s):  
Sung G. Pyo ◽  
Nack J. Kim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mechanical Alloying ◽  
Grain Boundaries ◽  
Hot Pressing ◽  
Analytical Transmission Electron Microscopy ◽  
Controlled Atmosphere ◽  
Mechanically Alloyed ◽  
Transmission Electron ◽  
Coarsening Behavior

AbstractNiAl intermetallic powder has been synthesized by mechanical alloying of elemental powders in an attritor mill using controlled atmosphere. The mechanically alloyed (MA) powders were consolidated by vacuum hot pressing (VHP), resulting in a material which was fully dense. Analytical transmission electron microscopy has been used to understand the development of microstructure with processing. The dispersoid particles present are mostly A12O3 with small amount of A1N. It has been shown that morphology of the dispersoid particles are not uniform and the larger dispersoid particles are located mostly along the grain boundaries with the dispersoid-free zones near them. Coarsening behavior of the dispersoid particles is different depending on their locations, i.e., within the grain or along the grain boundaries. The accelerated coarsening of dispersoids along the grain boundaries occurs concurrently with that of the grains and the formation of dispersoid-free zones (DFZs) are observed along the grain boundaries. It is suggested that this abnormal dispersoid coarsening and the formation of DFZ are due to the coupled migration of dispersoids and grain boundaries.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

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