Atomic-Resolution Electron Microscopy of TiB2 Precipitates in an Industrial TiAl Alloy

1996 ◽  
Vol 466 ◽  
Author(s):  
B. J. Inkson ◽  
G. Möbus ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Tial Alloy ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Resolution Electron ◽  
B2 Phase ◽  
Relationship Of ◽  
Orientational Relationship

ABSTRACTTiB2 nano-lamellae, grown in-situ within a TiAl intermetallic melt, have been examined by high resolution electron microscopy. The use of the Stuttgart ARM enables Ti and B columns to be distinguished in the HREM images. Examination of the internal structure of the T1B2 platelets reveals extensive prismatic faulting on {1010}TiB2, {0110}TiB2 and {1100}TiB2 planes. Externally, the TiB2 platelets exhibit an orientational relationship {1010}TiB2 // {001}B2 and [0001]TiB2 // <010>B2 with interleaving platelets of B2-phase, with the predominating interface planes being {1010}TiB2 // {001}B2. The minor facets of the TiB2 platelets are [0001]TiB2 // <010>B2. {0110}TiB2 and {1100}TiB2, with the latter two facets showing no relationship with the interleaving B2-phase. No preferred orientation relationship of the TiB2 with the surrounding γ-TiAl and α2-Ti3Al phases is observed.

High resolution electron microscopy observation of interfacial structures in NiAl-matrix in situ composites reinforced by TiC particulates

1997 ◽  
Vol 12 (7) ◽  
pp. 1790-1795 ◽  
Author(s):  
L. G. Yu ◽  
J. Y. Dai ◽  
Z. P. Xing ◽  
D. X. Li ◽  
J. T. Guo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Amorphous Layer ◽  
Interfacial Layers ◽  
Resolution Electron ◽  
Interfacial Structures ◽  
Tic Particulates ◽  
Nial Matrix

The structures of interfaces in NiAl-matrix in situ composites reinforced by TiC particulates were studied by means of high-resolution electron microscopy (HREM). No consistent orientation relationship between TiC particles and the NiAl matrix was found. In most cases, TiC particles bonded well to the NiAl matrix free from any interfacial phases. However, in some cases, an interfacial amorphous layer with a thickness of about 3 nm was found. The annealed NiAl–TiC composite showed a good chemical compatibility between the TiC particles and the NiAl matrix, though, some interfacial layers between TiC and NiAl, which were determined to be C-deficient TiC, were found. NiAl precipitates were observed in the TiC particles of the annealed specimens.

Surface studies in UHV: Applications of High-resolution electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 444-445
Author(s):  
M. R. McCartney ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Vacuum ◽  
High Resolution Electron Microscopy ◽  
Plan View ◽  
Voltage Electron ◽  
Resolution Electron ◽  
Video Systems ◽  
Electron Microscopes

The examination of surfaces requires not only that they be free of adsorbed layers but the environment of the sample must also be maintained at high vacuum so that the surfaces remain clean. The possibility of resolving surface structures with atomic resolution has provided the motivation for optimizing intermediate and high voltage electron microscopes for this particular application. Electron microscopy offers a variety of techniques which have the capability of achieving atomic level detail of surfaces including plan-view imaging, REM and profile imaging. Operation at higher voltages permits reasonable pole piece dimensions thereby providing space for in situ studies yet still compatible with high resolution. Moreover, video systems can be attached which permit observation and recording of dynamic phenomena without compromising microscope performance.

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