An Atomistic Description of Dealloying

We describe the microscopic details of porosity formation during dealloying as illuminated by a kinetic Monte Carlo model incorporating site coordination-dependent surface diffusion of all alloy components, and site coordination-dependent dissolution of the less-noble atoms. Our simulation model reproduces the entire range of phenomena associated with selective dissolution. These phenomena include composition and geometric restrictions on dealloying (parting limits), a composition-dependent critical potential, a passivation regime, a regime of steady-state dissolution flux, and porosity formation. We find that an intrinsic critical potential exists as a well-defined threshold potential separating surface…