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Electron-microscopy
- Transmission electron microscope Philips-CM30
[1]
- © Chair Metallic Materials
The microstructure analyses performed at the Chair
Metallic Materials range from the characterization with optical
microscopy (LM) and the analysis of precipitates and intermetallic
phases in a scanning electron microscope (SEM) up to the investigation
of distortion mechanisms in a transmission electron microscopy (TEM).
The preparation of the specimens for the optical microscopy, SEM and
TEM is carried out in the metallographic laboratory.
For the first characterization of the microstructure an optical
microscope of the brand Zeiss Axioskop with a4i-image-analysis as
well as microhardness testing system of the type Struers-Duramin is
available.
A SEM of the type Jeol 640 is available for
further investigations of the microstructure, as for example for the
analysis of fracture surfaces or fine surface structures. A built-in
Link-EDS-system allows the qualitative and quantitative analysis of
the chemical composition of precipitates and intermetallic
phases.
- CMSX-4, after creep: Dislocation loops at phase boundaries
[2]
- © Chair Metallic Materials
The specimens for the TEM investigations are prepared primarily by electrolytic thinning. The final preparation occurs by means of dimple grinder and an ionic-mill (Bal-Tec Res010). The TEM investigations are carried out with a Philips-CM 30 which is equipped with 11 Megapixel CCD camera (Gatan, Orius SC 1000) and a Voyager EDS system for the element analysis. The exact lighting of the specimen permits the determination of the microstructure and chemical composition in the submicrometer range. Therefore, it is possible to carry out investigations of dislocation movements in deformed microstructures. In this field a special expertise lies in the characterization of Nickel base super alloys.
X-Ray Diffractometry
- 2-D residual distribution of a rail surface along the rolling direction
[3]
- © Chair Metallic Materials
Complementary to the electron microskopy at the Chair Metallic Materials different laboratory X-ray diffractometers are available. With these systems analyses of the phase compositions, textures and residual stresses in engineering materials and components can be carried out. As a result of the penetration depth of the radiation of some micrometers X-ray diffractometry delivers information about the area close to the surface zone. The spatial resolution of laboratory scale X-ray diffractometers ranges according to the measuring procedure from approximately 100 mm2 up to approximately 10 mm2.
- Laboratory X-ray diffractometer with a position-sensitive detector
[4]
- © Chair Metallic Materials
The findings of these investigations are required for the validation of the results of the simulations accompanying the extrusion as well as for the interpretation of the macroscopic mechanical-technological properties and characteristic of the extrusion products. by the extensive knowledge of the microstructure and their correlation with the mechanical properties it is possible to optimize these by a defined alteration of the process parameters already during the extrusion process.
- Four-Circle-Diffractometer with glas capillary
[5]
- © Chair Metallic Materials
To be able to respond to the large variety of
technological questions, the X-ray diffractometers which are available
at the Chair Metallic Materials, are differently equipped. Thus X-ray
diffractometers equipped with scintillation and position-sensitive
detectors as well as with furnaces for investigations at elevated
temperatures are available.
In addition to the available
laboratory X-ray diffraction systems synchrotron X-ray sources such
as BESSY in Berlin, HASYLAB in Hamburg and ESRF in Grenoble are
frequently used.
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