Diffusion-driven microstructure evolution in OpenCalphad

Asymmetrical Exchange of Monomers for Constructing Hollow Nanoparticles and Antifragile Monoliths

“…Diffusion is driven by the minimization of Gibbs free energy. 35 Intuitively, it may be possible for us to break the diffusion symmetry by intensifying the outgoing diffusion of COF constituents through increasing the Gibbs free energy of COF nanoparticles. This is achievable by the introduction of particles with amorphous structures.…”

Numerical modeling of diffusion-controlled phase transformation using the Darken method: Application to the dissolution/precipitation processes in materials

“…This diffusion model, also called the bi-velocity method, was found to be consistent with the linear irreversible thermodynamics for a monophasic system [28]. It was shown to be efficient for multicomponent systems where the intrinsic fluxes of each component are coupled through the drift velocity [6,29,30]. This diffusion model, written through the derivative of diffusion potential, may include different driving forces such as mechanical stress induced by gravity [31] necessary to model segregation in multicomponent mixtures under gravity [32].…”

“…The interface displacement is thus related to the conservation of the mass balance at the interface. The approaches based on the Kampmann-Wagner numerical model, which describes nucleation, growth, and coarsening of spherical precipitates, are of great interest in solving such physical phenomena, since they give an insight into microstructure evolution characteristics such as the number of particles and their mean radius [5,6], and for specific times as regards the particle density distribution function [6]. As a complement to these approaches, for which particle morphology remains spherical, there is a need to better understand particle morphology changes during the processes.…”

Simulation of diffusion with non-equilibrium vacancies, Kirkendall shift and porosity in single-phase alloys

“…Diffusion simulations have become widely used to predict composition evolutions in high temperature materials, e.g. in alloy-coating systems or in alloys subject to selective oxidation [1][2][3][4][5][6]. In a substitutional alloy subject to vacancy-mediated diffusion, a composition gradient will generate diffusion, which in turn may have consequences associated with the Kirkendall effect [7][8][9][10].…”

“…Several numerical tools used today to simulate interdiffusion [1,2,4,5] rely on Ågren's formalism [18,19], which also considers an ideal lattice and therefore cannot, by construction, generate Kirkendall porosity. Methods were introduced [20][21][22] to estimate pore fractions as a post-processing step of simulations run in this configuration.…”