铝合金表面非晶碳薄膜在硫酸盐还原菌作用下的腐蚀行为

Corrosion behavior of an amorphous carbon film on surface of aluminum alloy under action of SRB

采用等离子体增强化学气相沉积技术在7A04铝合金表面制备类金刚石(DLC)薄膜,利用电化学阻抗谱与动电位极化曲线对基体与DLC薄膜在硫酸盐还原菌(SRB)中的腐蚀行为进行研究,通过红外光谱及拉曼光谱对腐蚀产物结构进行表征。实验结果表明,随着浸泡时间的增加,7A04铝合金自腐蚀电流密度从1.151×10^(-7)A/cm^(2)增大至1.968×10^(-5)A/cm^(2)。镀有DLC薄膜的铝合金的自腐蚀电流密度小于基体,且随着浸泡时间的增加变化不大,在SRB溶液中表现出优异的耐蚀性。红外光谱、拉曼光谱及电化学阻抗谱的结果表明,镀有DLC薄膜的7A04铝合金在SRB溶液浸泡过程中,表面吸附较多的微生物及其代谢产物,薄膜表面耦合微生物膜是抑制SRB腐蚀的主要原因。

In this paper,plasma-enhanced chemical vapor deposition technology was mainly used to prepare diamond-like carbon(DLC)films on the surface of 7A04 aluminum alloy,and the corrosion behavior of matrix and DLC films in sulfate-reducing bacteria(SRB)was studied by electrochemical impedance spectroscopy and potentiodynamic polarization curve.The structure of corrosion products was characterized by infrared spectroscopy and Raman spectroscopy.The experimental results show that with the increase of immersion time,the self-corrosion current density of 7A04 aluminum alloy increases from 1.151×10^(-7)A/cm^(2)to 1.968×10^(-5)A/cm^(2).The self-corrosion current density of aluminum alloy coated with DLC film is less than that of the matrix,and it does not change much with the increase of soaking time,showing excellent corrosion resistance in SRB solution.The results of infrared spectroscopy,Raman and electrochemical impedance spectroscopy showed that 7A04 aluminum alloy coated with DLC film adsorbed more microorganisms and their metabolites on the surface during the immersion process of SRB solution,and the coupling microbial film on the surface of the film was the main reason for inhibiting SRB corrosion.