The contribution of dislocations to the electrochemical reactions ocurring on the surface of face-centered cubic metals was explained in terms of long-range internal stresses with respect to dislocation patterns. In order to support the modelling approach, tensile straining effects upon the dissolution of polycrystalline Ni were investigated in 1M H2SO4 at 291K. It was demonstrated that a good correlation existed between dislocation distributions and current density. A thermodynamic analysis of the modification of the solid–liquid balance in the presence of dislocations was proposed in order to take account of dislocation patterns. A limitation of this approach was due to adsorption processes. In a manner similar to H adsorption, plastic strain seemed to promote adsorption at dislocation densities lower than 6 x 1013/m2. This was partially suppressed at higher dislocation densities, in accordance with the idea that geometrical and/or energetic disorder, developed by the concentration of dislocations in walls, led to the spacing of adsorption sites and thus to a decrease in the number of active adsorption sites.

The Effects of Dislocation Patterns on the Dissolution Process of Polycrystalline Nickel. M.Sahal, J.Creus, R.Sabot, X.Feaugas: Acta Materialia, 2006, 54[8], 2157-67