Operando odd random phase electrochemical impedance spectroscopy (ORP-EIS) for in-situ monitoring of the Zr-based conversion coating growth in the presence of (in)organic additives

Operando odd random phase electrochemical impedance spectroscopy (ORP-EIS) is introduced as an in-situ monitoring tool to directly monitor the conversion treatment of zinc in a hybrid Zr-based solution containing aminosilane and Cu additives. SEM and EDX are applied to investigate the morphology and elemental composition of the oxide film. Results show that the operando ORP-EIS provides an opportunity to investigate the growth of the conversion layer and its surface homogeneity as well as the charge transfer reaction during conversion. Moreover, the presence of aminosilane in the Zr solution containing Cu improves the morphology and barrier properties of the conversion film.