Dislocation relaxation processes due to kink migration
The interpretation of the Bordoni relaxation and of related relaxation phenomena in terms of the thermally activated, stress-assisted formation of kink pairs on dislocation lines is well established on assuming that the migration of kinks along dislocation lines is described by a high kink mobility...
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1996
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11554339_v6_n8_pC8_Hermida http://hdl.handle.net/20.500.12110/paper_11554339_v6_n8_pC8_Hermida |
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paper:paper_11554339_v6_n8_pC8_Hermida2023-06-08T16:09:19Z Dislocation relaxation processes due to kink migration Hermida, Elida Beatriz Differential equations Dislocations (crystals) Enthalpy Internal friction Relaxation processes Shear stress Activation enthalpy Bordoni relaxation Kink migration Kink mobility Kink pair formation Thermal kink Metals The interpretation of the Bordoni relaxation and of related relaxation phenomena in terms of the thermally activated, stress-assisted formation of kink pairs on dislocation lines is well established on assuming that the migration of kinks along dislocation lines is described by a high kink mobility μ k . This assumption, however, is not valid if the activation enthalpy for kink migration, H m , is comparable with or even larger than the formation enthalpy of kink pairs or if even when small compared with the formation energy of kinks, H m is larger than the lowest thermal energies accessible in internal friction experiments. In those cases not only migration but also annihilation and trapping of thermal kink pairs may produce internal friction peaks. The difference-differential equations governing the thermal kink pairs evolution along dislocation lines under the action of a homogeneous applied shear stress are set up and their time-dependent solutions characterized by a set of relaxation times. It is shown how to obtain, from these solutions, the internal friction spectrum under conditions that are experimentally realized. Quantitative descriptions of geometrical kink migration and kink pair evolution are compared with selected experimental results. Fil:Hermida, E.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1996 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11554339_v6_n8_pC8_Hermida http://hdl.handle.net/20.500.12110/paper_11554339_v6_n8_pC8_Hermida |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Differential equations Dislocations (crystals) Enthalpy Internal friction Relaxation processes Shear stress Activation enthalpy Bordoni relaxation Kink migration Kink mobility Kink pair formation Thermal kink Metals |
| spellingShingle |
Differential equations Dislocations (crystals) Enthalpy Internal friction Relaxation processes Shear stress Activation enthalpy Bordoni relaxation Kink migration Kink mobility Kink pair formation Thermal kink Metals Hermida, Elida Beatriz Dislocation relaxation processes due to kink migration |
| topic_facet |
Differential equations Dislocations (crystals) Enthalpy Internal friction Relaxation processes Shear stress Activation enthalpy Bordoni relaxation Kink migration Kink mobility Kink pair formation Thermal kink Metals |
| description |
The interpretation of the Bordoni relaxation and of related relaxation phenomena in terms of the thermally activated, stress-assisted formation of kink pairs on dislocation lines is well established on assuming that the migration of kinks along dislocation lines is described by a high kink mobility μ k . This assumption, however, is not valid if the activation enthalpy for kink migration, H m , is comparable with or even larger than the formation enthalpy of kink pairs or if even when small compared with the formation energy of kinks, H m is larger than the lowest thermal energies accessible in internal friction experiments. In those cases not only migration but also annihilation and trapping of thermal kink pairs may produce internal friction peaks. The difference-differential equations governing the thermal kink pairs evolution along dislocation lines under the action of a homogeneous applied shear stress are set up and their time-dependent solutions characterized by a set of relaxation times. It is shown how to obtain, from these solutions, the internal friction spectrum under conditions that are experimentally realized. Quantitative descriptions of geometrical kink migration and kink pair evolution are compared with selected experimental results. |
| author |
Hermida, Elida Beatriz |
| author_facet |
Hermida, Elida Beatriz |
| author_sort |
Hermida, Elida Beatriz |
| title |
Dislocation relaxation processes due to kink migration |
| title_short |
Dislocation relaxation processes due to kink migration |
| title_full |
Dislocation relaxation processes due to kink migration |
| title_fullStr |
Dislocation relaxation processes due to kink migration |
| title_full_unstemmed |
Dislocation relaxation processes due to kink migration |
| title_sort |
dislocation relaxation processes due to kink migration |
| publishDate |
1996 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_11554339_v6_n8_pC8_Hermida http://hdl.handle.net/20.500.12110/paper_11554339_v6_n8_pC8_Hermida |
| work_keys_str_mv |
AT hermidaelidabeatriz dislocationrelaxationprocessesduetokinkmigration |
| _version_ |
1768542280865546240 |