P. Fratzl et O. Penrose, ISING-MODEL FOR PHASE-SEPARATION IN ALLOYS WITH ANISOTROPIC ELASTIC INTERACTION .1. THEORY, Acta metallurgica et materialia, 43(8), 1995, pp. 2921-2930
Citations number
37
Categorie Soggetti
Material Science","Metallurgy & Metallurigical Engineering
We propose a model to study, on an atomistic scale, the effects of ela
stic misfit strains on the growth and coarsening of domains in phase-s
eparating alloys. The model considered is a two-dimensional square cry
stal lattice with periodic boundary conditions and with an A or B atom
near each site. To model the elastic interaction, nearest and next-ne
arest neighbours are connected by springs with longitudinal and transv
erse stiffnesses. In addition, there is a chemical interaction between
nearest neighbours, favouring like against unlike pairs. A mean field
analysis predicts phase separation into coherent phases, below a temp
erature which (for a typical set of elastic parameters) increases with
the strength of the elastic forces. This critical temperature is less
than that for separation into incoherent phases. The analysis also pr
edicts how the anisotropy determines the shapes of domains at early ti
mes. A Monte Carlo procedure for implementing Kawasaki dynamics to rep
resent diffusion in this model is described.