DISSOLUTION MECHANISM AND NEGATIVE DIFFERENCEEFFECT OF ALUMINUM BASED SACRIFICIAL ANODE
铝基牺牲阳极的溶解过程和负差异效应

The dissolution mechanism and negative difference effect (NDE) of aluminum sacrificial anode have been studied using rotating ring-disk electrode,electron probe techniques and morphological analysis.The results show that dissolution of the anode initiates at boundary of second phase particles and results in damage of surface passive film and activation. NDE observed in anodic dissolution of the anode is mainly attributed to self-dissolution of naked and activated aluminum, which increases Droporticnallv with impressed anodic current. The NDE coefficient of the anode was measured to be 12.8%.