Demonstration of a novel rotating cylindrical electrode in growth of oxide films with spatially controlled microstructural variation on al 6061

摘要

We report growth and characterization of oxide films with spatiallycontrolled microstructure on Al 6061 using a coaxial rotating, axially translating electrochemical reactor (CRATER). The instrument allows oxide film growth with spatially controlled microstructure on a single working electrode (WE) under well-defined conditions of mass transfer, electrode potential, and residence time. This is achieved by restricting electro-oxidation to a "window" of narrow axial extent just below the free surface of an electrolyte whose coaxial inner and outer boundaries are a rotating counterelectrode and an axially translating WE, respectively. Axial variation of oxide microstructure on the WE reported here corresponds to temporal variation of potential during WE ascent, with remarkable monodispersity and azimuthal uniformity of pore size distribution. Continuous scanning of process variables in a single experiment by this approach allows identification of desirable microstructures in narrow ranges of operating conditions. Application of CRATER methodology to electrodissolution and electrodeposition is discussed.