A thermokinetic model for Mg-Si couple formation in Al-Mg-Si alloys

0464046 - ÚFM 2017 RIV GB eng J - Článek v odborném periodiku
Svoboda, Jiří - Shan, Y. V. - Kozeschnik, E. - Fischer, F. D.
A thermokinetic model for Mg-Si couple formation in Al-Mg-Si alloys.
Modelling and Simulation in Materials Science and Engineering. Roč. 24, č. 3 (2016), č. článku Art. Num. 035021. ISSN 0965-0393. E-ISSN 1361-651X
Grant CEP: GA ČR(CZ) GA14-24252S
Institucionální podpora: RVO:68081723
Klíčová slova: aluminium alloys * cluster assisted nucleation * kinetics * bulk diffusion * thermodynamic modelling
Kód oboru RIV: BJ - Termodynamika
Impakt faktor: 1.891, rok: 2016

Mg-Si couples formed from atomic Mg and Si represent the first step in Mg-Si cluster formation in a dilute Al-Mg-Si system. Based on the thermodynamic extremal principle, a kinetic model for Mg-Si couple formation is developed. The model utilizes the trapping concept for the calculation of Gibbs energy of the non-equilibrium system and provides a generalized (multiplicative) form of the Oriani equation for description of the equilibrium state. The dissipation in the system accounts for diffusion of both Mg and Si atoms in the lattice. The model is compared with the classical Lidiard and Howard equilibrium theory. Some demonstrative examples are presented. Finally the model is applied to an experimentally studied system. Good quantitative agreement with quenching experiments is obtained, if, simultaneously, the impact of excess quenched-in vacancies and their gradual annihilation in the system, which has been already treated in a previous paper, are accounted for. The model is generally applicable for any couple (and pair) formation.
Trvalý link: http://hdl.handle.net/11104/0263114