摘要
随着海洋资源开发战略的深入推进,具有优异耐蚀性的纯钛在海洋工程装备中的广泛应用面临微生物腐蚀的严峻挑战.本研究以海洋优势菌种铜绿假单胞菌(Pseudomonas aeruginosa,P.aeruginosa)为研究对象,通过细菌培养、电化学测试、表面形貌表征及腐蚀产物分析研究了纯钛的微生物腐蚀行为,系统揭示了TA2纯钛在生物膜作用下的腐蚀失效机制.研究表明,P.aeruginosa加速了TA2纯钛的腐蚀进程:在含菌环境浸泡初期,生物膜通过物理屏障效应暂时对基体起到保护作用;随浸泡时间的延长,生物膜脱落,表面点蚀深度较无菌环境增大,电荷转移电阻降低,腐蚀电流密度增大.一方面,有菌环境下表面钝化膜中TiO_(2)含量下降,亚稳态Ti_(2)O_(3)/TiO的生成使膜层致密性降低,形成局部缺陷并诱发点蚀萌生;另一方面,P.aeruginosa可能通过分泌绿脓菌素(pyocyanin,PYO)等电子载体介导细菌和金属间的电子传递.研究成果为海洋装备的腐蚀预测与微生物防护技术开发提供了理论支撑,对提升海洋工程材料的服役安全性与经济性具有重要意义.
With the deepening of the strategy of marine resources development,the wide application of pure titanium with excellent corrosion resistance in marine engineering equipment is facing the severe challenge of microbiologically influenced corrosion(MIC).In this study,the microbial corrosion behavior of pure titanium was investigated through bacterial culture,electrochemical testing,surface morphology character ization and corrosion product analysis with the dominant marine bacterial species Pseudomonas aeruginosa(P.aeruginosa)as the research ob ject.This study systematically revealed the corrosion failure mechanism of TA2 pure titanium under the action of biofilm.Results showed that P.aeruginosa accelerated the corrosion process of TA2 pure titanium.At the initial stage of immersion in a bacterial-containing environment,the biofilm temporarily protected the substrate through the physical barrier effect.With the prolongation of immersion time,the biofilm detached,and the depth of surface ptting increased compared with that in the sterile environment,with the decrease of charge transfer resistance and the increase of corrosion current density.On the one hand,the TiO_(2)content in the surface passivation film decreased in the bacterial environment,and the formation of metastable Ti_(2)O_(3) reduced the compactness of the film layer,formed local defects and induced pitting initiation.On the other hand,P.aeruginosa might mediate electron transfer between bacteria and metals by secreting electron carriers such as pyocyanin(PYO).Generally,the research results provide theoretical support for the corrosion prediction of marine equipment and the development of microbial protection technologies,which is of great significance to enhance the service safety and economic efficiency of marine engineering materials.
作者
冉博元
强玉杰
杨昊轩
金莹
RAN Boyuan;QIANG Yujie;YANG Haoxuan;JIN Ying(National Center for Materials Service Safety,University of Science and Technology Beijing,Beijing 100083,China)
出处
《材料保护》
2025年第8期31-43,共13页
Materials Protection
基金
国家重点研发计划(2022YFA1603803)。
关键词
微生物腐蚀
纯钛
铜绿假单胞菌
腐蚀机理
microbiologically influenced corrosion
pure titanium
Pseudomonas aeruginosa
corrosion mechanism
