On the Mechanism of the A.C. Electrolytic Graining of Rolled Aluminium Substrates

SummaryThe roughening of aluminium lithographic sheet is most commonly carried out by a.c. electrolytic graining. An electrochemical investigation of the mechanism of the anodic electrode processes involved in the electrograining of aluminium is presented. The role of the anodic processes in the development of a distinct surface morphology is established. The investigation involves potential step experiments in a dedicated wall-jet electrode reactor, allowing the mechanism of the oxidation of aluminium during the a.c. electrolytic graining to be investigated in a hydrodynamic steady state. Moreover, the role of mass transport in the overall kinetics of the electrode processes can be determined. For the analysis of the potentiostatic transient behaviour, a numerical computational method is presented, based on a second-order-correct implicit finite difference approach.