Local Cell Action during the Scaling of Metals, I

When a tantalum wire partly covered by silver is exposed to iodine vapor at 174°C, a layer is formed not only on silver but also rapidly along the tantalum surface by virtue of local cell action involving migration of silver ions in and migration of electrons in the tantalum wire and across the layer. The observed rate of sidewise growth of the layer along the tantalum surface is in accord with theoretical calculations. By and large, local cell action may increase the rate of dry corrosion when there are different phases, one of which involves easy flow of ions and another involves easy flow of electrons.