Diffusion-controlled phase growth on dislocations

Ali R Massih (1)

1 Quantum Technologies AB

We treat the problem of diffusion of solute atoms around screw dislocations. In particular, we express and solve the diffusion equation in 2-dimensions with radial symmetry in an elastic field of a screw dislocation subject to conservation of flux at the interface of a new phase. We consider an incoherent second-phase precipitate growing under the action of the stress field of a screw dislocation. The second-phase growth rate as a function of the supersaturation and a strain energy parameter is evaluated in spatial dimensions d=2. Our calculations show that an increase in the amplitude of dislocation force, e.g. the magnitude of the Burgers vector, enhances the second-phase growth in an alloy. Moreover, we calculate reduction in concentration of solute atoms as a function of radius around a second-phase which grows cylindrically (radial direction) so that its radius varies as a square root of time for various levels of the dislocation force amplitude.

Mots clés: Physical Sciences

Ali R Massih. Diffusion-controlled phase growth on dislocations. Philosophical Magazine, 2009, 89 (33), pp.3075-3086. ⟨10.1080/14786430903181113⟩. ⟨hal-00529577⟩