| Abstract Scope |
Dealloying techniques to produce open porous or bicontinuous structures have flourished during the past decade. Existing techniques include electrochemical dealloying (ECD), liquid metal dealloying (LMD), solid-state dealloying, and vapor phase dealloying (VPD), introduced relatively recently, which exploits the selective evaporation of one element on an alloy.
Experiments have revealed that the kinetics of VPD switches from ECD-like interface-controlled kinetics at the early stage of dealloying followed by LMD-like diffusion-controlled kinetics at a later stage. Modeling VPD is made especially challenging by the fact that the mean free path of evaporating atoms in the vapor state is much larger than the pore size, which makes transport in the vapor phase pore-size dependent (Knudsen diffusion). We report the results of a simulation study of VPD structures and kinetics using a novel kinetic Monte-Carlo (KMC) algorithm that models simultaneously selective evaporation, surface diffusion, and geometrically confined vapor phase transport. |