Chemically and Mechanically Driven Creep Due to Generation and Annihilation of Vacancies with Non-ideal Sources and Sinks

0363691 - ÚFM 2012 RIV US eng J - Článek v odborném periodiku
Fischer, F. D. - Svoboda, Jiří
Chemically and Mechanically Driven Creep Due to Generation and Annihilation of Vacancies with Non-ideal Sources and Sinks.
International Journal of Plasticity. Roč. 27, č. 9 (2011), s. 1384-1390. ISSN 0749-6419. E-ISSN 1879-2154
Grant CEP: GA ČR GAP204/10/1784
Výzkumný záměr: CEZ:AV0Z20410507
Klíčová slova: Creep * Stress relaxation * Crystal plasticity
Kód oboru RIV: BJ - Termodynamika
Impakt faktor: 4.603, rok: 2011

The classical concept of Nabarro creep is extended for a general dislocation microstructure. The specific mechanism of the creep consists in generation and annihilation of vacancies at dislocation jogs acting as non-ideal sources and sinks for vacancies. This mechanism causes the climb of dislocations, allowing for local volume and shape change. The final kinetic equations, relating the dislocation microstructure and the local stress state to the creep rate, are derived by means of the thermodynamic extremal principle. Closed-form equations for the creep rate are derived for isotropic polycrystals. Based on the model the creep rate in the ferritic P-91 type steel at very low applied stress is evaluated and compared with experiment.
Trvalý link: http://hdl.handle.net/11104/0199399