It was recalled that the thermodynamics of grain-boundary wetting led to an imbalance between the grain boundary and solid-liquid interphase surface tensions. This in turn created a force which acted at the root of the grain-boundary groove and pointed into the solid. The so-called indentation-action of this force was suggested to cause stress-driven self-diffusion into the grain boundary. This process removed solid atoms from the groove cavity and caused their deposition along the grain boundary. Upon assuming that the grain boundary acted as a perfect sink, this self-indentation internal solution mechanism could then account for a number of features of grain-boundary wetting. These included non-Mullins grooving morphologies and linear kinetics, the appearance of singular stress fields at the wetting front, expansion of the solid during grain-boundary wetting, the effect of external stress upon grain-boundary wetting, wetting transitions as a function of temperature, and rapid penetration of liquid metal ahead of the groove root.

On the Kinetic Mechanism of Grain Boundary Wetting in Metals. E.E.Glickman, M.Nathan: Journal of Applied Physics, 1999, 85[6], 3185-91