| Autor: |
William J. Pardee, H.E Cook |
| Rok vydání: |
1977 |
| Předmět: |
|
| Zdroj: |
Acta Metallurgica. 25:1403-1412 |
| ISSN: |
0001-6160 |
| DOI: |
10.1016/0001-6160(77)90071-2 |
| Popis: |
A theoretical model is given for the two internal friction peaks found in omega forming alloys. Third-order coupling between the applied wave and two quasi-static waves associated with omega heterophase fluctuations is found to be sufficient to cause the observed internal friction. Strong third-order coupling is predicted by the symmetry change associated with the transition. The two peaks which have been observed are postulated to result from the growth (decay) anisotropy of an omega embryo. The relaxation time is strongly temperature dependent as thermal activation is required for jumps between the stable and metastable states. The activation energy for the low temperature peak is predicted to be 1 6 the value of the high temperature peak in agreement with experiment. The model predicts that the internal friction should become very large as the athermal omega phase boundary is approached. The calculated value of the internal friction is found to be roughly an order of magnitude higher than the measured value. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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