摘要
采用失重法分析5754铝合金在含海洋常见微生物枯草芽孢杆菌(B.subtilis)的海水中的腐蚀行为,利用SEM和白光干涉仪分别观察了表面腐蚀产物形貌及腐蚀轮廓,并用EDS和XRD分析了表面腐蚀产物成分,最后利用EIS研究该铝合金的腐蚀机理。结果表明,浸泡在含有微生物B.subtilis的海水环境中,铝合金腐蚀速率为12.5 mg/(dm^2·d),仅为浸泡在不含有微生物海水环境中铝合金腐蚀速率的1/6。浸泡在含有B.subtilis的海水环境中,铝合金表面逐渐形成一层以CaMg(CO3)2为主要成分的矿化物质膜,微生物B.subtilis的存在促进了生物矿化膜的形成,阻碍了海水对铝合金的侵蚀,从而抑制了铝合金在海水环境中的点蚀。
Currently,with the gradual depletion of onshore resources,more efforts are being devoted to both scientific and resource exploitation of the ocean and the deep sea.Compared with the onshore environment,marine habitats are complex and characterized by high hydrostatic pressure,high salinity,and high marine population.The ocean is a unique aquatic environment,and it has a large population of microorganisms.There is a need to exploit the ocean for new energy sources.The significant challenges of exploiting oil,gas,and minerals have forced the people to innovate and develop advanced exploration tools.Al alloys are attractive for use in marine environments due to their low densities,high strengths,good plasticity,excellent electrical and thermal conductivities,and excellent corrosion resistance.The high chloride concentrations and microorganisms in the ocean have a significant effect on the corrosion resistance of many metallic materials.In this work,the corrosion behavior of 5754 Al alloy in seawater containing B.subtilis was investigated.The corrosion rate was analyzed by the weight loss method.The morphologies of the corrosion products and the corrosion profiles were observed by SEM and white light interferometer,respectively.The corrosion products were analyzed by energy dispersive spectroscopy and XRD.Finally,the corrosion mechanism of the Al alloy was studied using electrochemical impedance spectroscopy.The results show that the corrosion rate of the Al alloy in the seawater with B.subtilis was 12.5 mg/(dm^2·d),which was only 1/6 times that in the seawater without the bacteria.A protective film comprising of CaMg(CO3)2 was gradually formed on the surface of the alloy in the presence of the bacteria.The bacteria promoted the formation of the CaMg(CO3)2 film,which protected the alloy from the seawater,and consequently,inhibited the pitting corrosion of the Al alloy in the marine environment.
作者
申媛媛
董耀华
董丽华
尹衍升
SHEN Yuanyuan;DONG Yaohua;DONG Lihua;YIN Yansheng(College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第12期1681-1689,共9页
Acta Metallurgica Sinica
基金
国家自然科学基金项目No.51609133。
