Al-Zn-In牺牲阳极在不同工作电流密度下电流效率及溶解机制的研究

Current Efficiency and Corrosion Mechanism of Al-Zn-In Sacrificial Anode at Different Current Densities

采用电化学方法测定了Al-Zn-In牺牲阳极在不同工作电流密度下的电流效率和溶解机制。结果表明,工作电流密度的变化会引起Al-Zn-In牺牲阳极溶解机制发生改变,从而引起电流效率发生变化。在较小的工作电流密度下,Al-Zn-In牺牲阳极的电流效率异常降低,其原因可能是In3+和Zn2+等离子的再沉积过程受到抑制,使Al-Zn-In牺牲阳极表面形成一层氧化膜。氧化膜的破裂和溶解过程不会产生电流,而能引起牺牲阳极的质量损耗,导致阳极电流效率小于理论值。

The current efficiency and corrosion mechanism of Al-Zn-In sacrificial anode by different impressed current densities were investigated by using electrochemical methods. Results showed that the corrosion mechanism and the current efficiency of the Al- Zn- In sacrificial anode varied with the impressed current densities. The current efficiency decreases dramatically by a low current density, this may be caused by the fact that the re-deposition of the dissolved cations(In3 +,Zn2 +) was suppressed and an oxides film might formed on the alloy surface. A mass loss of the anode might be caused by the cracking and dissolving of the oxides film, and this might be responsible to the current efficiency of Al-Zn-In sacrificial anode lower than that theoretically expected by the low impressed current density.