Scale-Bridging Thermodynamic and Kinetic Simulation (STKS)
Phase-field simulation of diffusion couples in the Ni-Al system
L. Zhang, I. Steinbach, Y. Du.
International Journal of Materials Research, International Journal of Material Research, 102, 371-380, (2011)
By linking thermodynamic and atomic mobility databases with two-dimensional phase-field simulation, the evolution of interdiffusion microstructures in a series of Ni-Al diffusion couples associated with the γ,γ′, and β-phases was studied. The formation and subsequent growth of the γ′-phase layer in β/γ and γ′+β/γ diffusion couples reproduced the experimental observations well. Moreover, the effect of coherent strain on the γ-γ′ microstructural evolution, as well as that of an external compressive force on the γ+γ′/γ+γ′ diffusion couple, was investigated. The phase-field simulated concentration profiles of some of the Ni-Al diffusion couples were also compared with the corresponding experimental data and the results of one-dimensional DICTRA (DIffusion Controlled TRAnsformations) simulations. A discussion of the rafting direction was also made by comprehensively results from an elastic model.
Keyword(s): Ni-Al diffusion couple; interdiffusion; phase-field simulation; precipitation; rafting