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Competence Group Metallography
Contact: Dr. Ulrich Burkhardt
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The main focuses of the experimental work are the preparation of metallographic microstructures and the characterisation of the materials by light optical and scanning electron microscopy. The aims are reliable phase analyses by energy- and wavelength dispersive x-ray spectroscopy as well as qualitative and quantitative evaluation of metallographic microstructures.
The equipment for sampling, embedding and preparation of metallographic microstructures is mainly suitable and optimized for the handling of metals and metallic alloys. Additionally, a complete set of modified equipment is arranged in a glove-box under Argon atmosphere. It allows the metallographic investigation of air and water sensitive samples like rare earth metal rich alloys or carbometallates. (Fig. left: multiphase microstructure of a carbon-rich sample of the system Er-Fe-C, bright filed image)
Investigations of the morphology of crystals and crystallites as well as phase analyses by energy-dispersive- x-ray spectroscopy (EDXS) are realised on a scanning electron microscope XL30 with LaB6 cathode (Fig. left: VB2 crystals; SE - contrast).
Advanced phase analyses on metallographic microstructures by wavelength- dispersive x-ray spectroscopy methods (WDXS) are performed on the Cameca SX100 electron-microprobe with W-cathode (Fig. left: multiphase microstructure of a gallium-rich alloy of the system Mg-Ag-Ga, BSE-contrast). The significant enhanced spectral resolution and the comparative measurements on reference materials results improved determinations of chemical composition and more accurate analyses of light elements. Especially, systematic analyses are performed on intermetallic borides.
EDX vs WDX:
left - partial sepctra of VB2 (ca 400 eV)
right - partial spectra of Zr2PTe2 (ca. 2 keV)