| Autor: |
Brokmeier, H.-G., Yi, S. B., Schwebke, B., Homeyer, J. |
| Jazyk: |
angličtina |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
Zeitschrift für Kristallographie / Supplements 26(2007), 159-164 (2008). doi:10.1524/9783486992540-025 |
| Popis: |
Hard X-rays with energies higher than 50 keV are characterized by there high penetration length in most materials. In the case of 100 keV to 200 keV X-rays the penetration length is in the same order as for thermal neutrons. Texture development belongs to one of the major characteristics of materials processing such as deformation and recrystallization. Using two examples a brief description is given for in-situ experiments carried out at the high energy beam line BW5. In contrast to in-situ strain measurements texture measurements are time consuming, so that the number of this type of experiments is still low. In order to describe the influence of the initial texture on the materials anisotropy texture simulations (VPSC model) and in- situ texture analyses were combined. Loading experiments comparable to standard material tests (stress-strain-curve) were carried out on magnesium-alloys in tension as well as in compression using a 20 kN loading device. Due to the high penetration length of 100 keV X-rays DIN 50125 samples of 6mm in diameter were used in transmission mode. In addition to standard texture measurements at the initial state and after failure up to five points at the known stress strain curve were chosen for in-situ texture measurements. An image plate detector covers a set of complete Debye-Scherrer cones, so that only -scans are necessary to get complete pole figures and the whole experiment is fast. It is even fast enough to perform high temperature experiments, which are very sensitive time dependent reactions. Two types of furnaces are available, one which can be combined with the loading device and a stand alone furnace. In many materials a phase and texture transition takes place during processing. The second example describes our first in-situ high temperature experiment on a steel sample to investigate the phase and texture transition (ferrite – austenite). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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