A diffuse interface phase field model is proposed for the unified analysis of diffusive and displacive phase transitions under nonisothermal conditions. Two order parameters are used for the description of the phenomena: one is related to the solute mass fraction and the other to the strain. The model governing equations come from the balance of linear momentum, the solute mass balance (which will lead to the Cahn-Hilliard equation) and the balance of internal energy. Thermodynamic restrictions allow to define constitutive relations for the thermodynamic forces and for the mechanical and chemical dissipations. Numerical tests carried out at different values of the initial temperature show that the model is able to describe the main features of both the displacive and the diffusive phase transitions, as well as their effect on the temperature.
A model for diffusive and displacive phase transitions: Thermo-chemo-mechanical coupling effects / M. Maraldi; G. N. Wells; L. Molari; P.G. Molari. - ELETTRONICO. - (2010), pp. 1-4. (Intervento presentato al convegno AES-ATEMA'2010 INTERNATIONAL CONFERENCE tenutosi a Le Quebec nel 27 june - 3 july 2010).
A model for diffusive and displacive phase transitions: Thermo-chemo-mechanical coupling effects
MARALDI, MIRKO;MOLARI, LUISA;MOLARI, PIER GABRIELE
2010
Abstract
A diffuse interface phase field model is proposed for the unified analysis of diffusive and displacive phase transitions under nonisothermal conditions. Two order parameters are used for the description of the phenomena: one is related to the solute mass fraction and the other to the strain. The model governing equations come from the balance of linear momentum, the solute mass balance (which will lead to the Cahn-Hilliard equation) and the balance of internal energy. Thermodynamic restrictions allow to define constitutive relations for the thermodynamic forces and for the mechanical and chemical dissipations. Numerical tests carried out at different values of the initial temperature show that the model is able to describe the main features of both the displacive and the diffusive phase transitions, as well as their effect on the temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
