Micro-galvanic corrosion of Cu/Ru couple in potassium periodate (KIO4) solution.

This paper focuses on the study of micro-galvanic corrosion of the Cu/Ru couple in KIO 4 solution. Practical nobility across the Cu/Ru interface was evaluated by Volta potential mapping, and the morphological changes were monitored by in-situ atomic force microscopy measurements during exposure in a KIO 4 solution. Chemical composition of precipitated corrosion product was analyzed by Confocal Raman spectroscopy immediately after the exposure. The results show that Cu is the anode of the Cu/Ru couple, and accelerated dissolution of Cu preferentially occurs near the Cu/Ru interface. However, subsequent formation of insoluble Cu(IO 3 ) 2 ·nH 2 O leads to precipitation, which impedes further Cu corrosion. [ABSTRACT FROM AUTHOR]