A systematic study based upon self-consistent dynamic simulations was presented for the grain boundary thermal grooving problem by strictly following the irreversible thermodynamic theory of surfaces and interfaces with singularities (Ogurtani, 2006). This approach furnished auto-control of the otherwise free motion of the grain boundary triple junction without presuming any equilibrium dihedral (wetting) angles at the edges. The effects of physicochemical properties and the anisotropic surface diffusivity on the transient grooving behaviour, which took place in the early stage of the scenario, were considered. The experimental thermal grooving data reported for tungsten in the literature were analyzed, and compared with the simulation results. This investigation showed that the observed changes in the dihedral angles were strictly connected to the transient behaviour of the simulated global system, and manifest themselves at the early stage of the thermal grooving phenomenon.

Mesoscopic Nonequilibrium Thermodynamics Treatment of the Grain Boundary Thermal Grooving Induced by the Anisotropic Surface Drift Diffusion. O.Akyildiz, E.E.Oren, T.O.Ogurtani: Journal of Materials Science, 2011, 46[18], 6054-64