Interaction of liquid and solid gallium with thin silver films: Synchronized spreading and penetration

The synchronized lateral spreading and through-penetration of liquid and solid gallium (Ga) in supported thin polycrystalline films of silver (Ag) were studied. The spreading and penetration kinetics were presumably controlled by a common mechanism. The spreading rate in the 0.5 mu m thick film was found to be constant with time. The activation energies of the process responsible for spreading/penetration of liquid and solid Ga were E-L approximate to 28.9 +/- 4.8 kJ mol(-1) and E-S approximate to 48.2 +/- 9.6 kJ mol(-1), respectively. Grain boundary grooving, with Ag diffusion out of the groove either through liquid Ga or through solid Ga, was suggested as a possible mechanism of the spreading and penetration. The model proposed reproduced the observed spreading/penetration rates and gave reasonable estimates of the energies E-S and E-L. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.