The melting of alloys along grain boundaries was considered as a free boundary problem for two moving solid/liquid interfaces. One of them was the melting front and the other was the solidification front. The presence of the triple junction played an important role in controlling the velocity of this process. The interfaces interacted strongly via the diffusion field in the thin liquid layer between them. In the liquid film migration mechanism, the system chose a more efficient kinetic path which was controlled by diffusion in the liquid film over relatively short distances. However, a weak coherency strain energy was the only effective driving force for liquid film migration in the case of the melting of one-phase alloys. The process with only one melting front could be controlled by the very slow diffusion in the parent solid phase over relatively large distances.

Steady-State Migration of the Liquid Film along a Grain Boundary During Melting of Alloys. E.A.Brener, D.E.Temkin: Acta Materialia, 2008, 56[10], 2290-5