Dissolution of binary alloy films formed on foreign substrates Available to Purchase

The electrodissolution of binary alloy films formed on inert substrates is a subject of recent origin. The Cu‐Au and Cu ‐30 per cent alloys, when dissolved anodically, showed a selective dissolution of the less noble metal occurring earlier than the simultaneous dissolution of both the components of the binary alloy films. However, the mode of dissolution, either galvanostatic or potentiostatic, varied the mechanism of dissolution. In the galvanostatic mode of dissolution, the dissolution changed from a preferential to a simultaneous one, while in the potentiodynamic type, simultaneous dissolution occurred. In the case of an ideal solid solution of Cu‐Ni alloy, under linear sweep conditions, an intermediate phase and an intermetallic compound dissolved simultaneously. Only for the eutectic types of alloy like Cu‐Pb and Cd‐Zn the dissolution was selective. On the other hand, Swathirajan considered that the dissolution was always preferential for the less noble metal.