The phase-field approach and solute drag modeling of the transition to massive gamma ->alpha transformation in binary Fe-C alloys
2003 (English)In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 51, no 5, 1327-1339 p.Article in journal (Refereed) Published
The transition between diffusion controlled and massive transformation gamma --> alpha in Fe-C alloys is investigated by means of phase-field simulations and thermodynamic functions assessed by the Calphad technique as well as diffusional mobilities available in the literature. A gradual variation in properties over an incoherent interface, having a thickness around 1 nm, is assumed. The phase-field simulations are compared with a newly developed technique to model solute drag during phase transformations. Both approaches show qualitatively the same behavior and predict a transition to a massive transformation at a critical temperature below the T-0 line and close to the alpha/alpha + gamma phase boundary. It is concluded that the quantitative difference between the two predictions stems from different assumptions on how the properties vary across the phase interface yielding a lower dissipation of Gibbs energy by diffusion in the phase-field simulations. The need for more detailed information about the actual variation in interfacial properties is emphasized.
Place, publisher, year, edition, pages
2003. Vol. 51, no 5, 1327-1339 p.
diffusion, thermodynamics, Gibbs energy, dissipation, interfacial properties, diffusional transformations, austenite, ferrite, growth, solidification, simulations
IdentifiersURN: urn:nbn:se:kth:diva-22341DOI: 10.1016/s1359-6454(02)00527-xISI: 000181677700011OAI: oai:DiVA.org:kth-22341DiVA: diva2:341039
QC 201005252010-08-102010-08-10Bibliographically approved