铜在含氯薄液膜和杂色曲霉作用下的腐蚀行为

目的 研究纯铜在含氯液膜和霉菌共同作用下的腐蚀行为与机理。方法 将海南文昌采集的一株野生杂色曲霉接种到质量分数分别为0.9%和3.5%的NaCl溶液中制成孢子悬浮液,将孢子悬浮液均匀喷洒到铜试样表面后进行恒温恒湿试验,试验不同周期后采用体视学显微镜、扫描电子显微镜观察铜试样的腐蚀形貌,采用X射线光电子能谱仪分析试验14 d的试样表面和氩离子刻蚀15 s后的成分。结果 纯铜在NaCl薄液膜下的腐蚀产物具有明显的双层结构,内层靠近基体的为致密的Cu2O钝化层,外层为疏松的Cu2(OH)2CO3和Cu2(OH)3Cl组成的Cu(II)碱式盐;无菌时,铜表面出现大量蓝绿色的Cu(II)碱式盐,杂色曲霉存在时,铜表面腐蚀产物主要为红棕色的Cu2O钝化膜,仅有少量Cu(II)碱式盐零星分布在Cu2O膜外层;0.9% NaCl薄液膜与霉菌共同作用时,试样表面腐蚀产物主要为Cu2O,当薄液膜中盐的质量分数升高到3.5%时,霉菌数量减少,Cu(II)碱式盐较0.9% NaCl薄液膜组增多。结论 纯铜的腐蚀产物由内层的Cu2O钝化层、外层的Cu2(OH)2CO3和Cu2(OH)3Cl组成双层结构。杂色曲霉通过呼吸作用影响液膜中的O2浓度进而影响铜的腐蚀产物组成,霉菌存在时腐蚀产物中Cu(II)碱式盐显著减少。含氯液膜与霉菌共同作用时,液膜中的NaCl浓度通过影响杂色曲霉的生长活性而影响腐蚀产物组成。     

霉菌对裸铜和镀金处理的印制电路板腐蚀行为的影响

采用扫描Kelvin探针测试技术研究了裸铜印制电路板(PCB-Cu)和无电镀镍金处理印制电路板(PCB-ENIG)在霉菌作用下的腐蚀行为,通过体视学显微镜、扫描电镜和能谱分析对PCB的腐蚀和霉菌生长情况进行了观察和分析.结果表明,在湿热环境下霉菌在2种材料表面均能良好生长并且数量逐渐增加,28 d完成一个生长代谢周期且分生孢子活性良好;84 d后试样表面都出现了腐蚀产物,PCB-ENIG腐蚀更为严重.霉菌的生长代谢作用在一定程度上能抑制PCB-Cu表面霉菌生长区域的腐蚀,但是对PCB-ENIG的微孔腐蚀起促进作用.     

热带雨林环境中霉菌对PCB-Cu腐蚀行为的影响

目的 研究PCB-Cu在热带雨林环境下的霉菌腐蚀行为。方法 利用平板培养法筛选出PCB表面出现频率较高的两株真菌Fusarium solani和Daldinia eschscholtzii。利用干重法研究Cu2+对其生理活性的影响,利用扫描电子显电镜观测PCB-Cu表面的生物成膜情况,并利用动电位极化曲线研究其腐蚀电化学行为。 结果 两株真菌在6天时,均能在PCB-Cu表面形成生物膜,且在菌丝密集处,出现腐蚀产物的堆积。同时,薄液膜内Cu2+浓度的升高能抑制菌体的繁殖。相比于无菌组,两株菌株均能够在前期抑制PCB-Cu自腐蚀电位Ecorr的升高,在后期抑制PCB-Cu自腐蚀电位Ecorr的降低。结论 霉菌孢子接种到PCB-Cu表面后,由于初期PCB-Cu表面薄液膜中的Cu2+含量较少,对菌体的抑制作用较低,因此菌体活性较好,其分泌物抑制了PCB-Cu表面氧化膜的生成,从而在初期促进了PCB-Cu的腐蚀。但随着腐蚀反应的进行,PCB-Cu表面薄液膜中Cu2+浓度逐渐升高,菌体的活性受到抑制,因此腐蚀性分泌物含量下降,而此时附着在PCB-Cu表面的生物膜对基体起到了保护作用,从而开始抑制腐蚀。     

在役环境磁场对L360管线钢及焊接接头腐蚀行为的影响

为明确磁场对L360输油管道腐蚀行为的影响,通过电化学测试及腐蚀形貌观察等手段,研究了L360管线钢母材及其焊接接头在不同强度磁场作用下3.5%NaCl溶液中的腐蚀行为。结果表明：随着磁场强度的增大,L360管线钢母材及其焊接接头的电荷转移电阻先增大后减小,腐蚀电流密度先减小后增大,较低强度磁场(60 mT)抑制了腐蚀,而较高强度磁场(120 mT)加速了腐蚀。相同磁场强度下,焊接接头腐蚀速率大于母材。机理分析表明：磁场作用力诱导金属离子吸附于电极界面,形成腐蚀产物膜阻碍腐蚀进行;高强度磁场作用下,Lorentz力能够破坏腐蚀产物膜,加速离子扩散,进而加速金属腐蚀。     

平行磁场对含V型缺陷的管线钢的腐蚀行为影响

目的 研究平行磁场对含V型腐蚀缺陷的X70管线钢在库尔勒土壤模拟溶液中的腐蚀行为影响。方法 利用失重法来计算含V型腐蚀缺陷的X70管线钢在不同平行磁场强度下的腐蚀速率。采用扫描电子显微镜和X射线光电子能谱(XPS)对V型槽槽内外腐蚀样貌及腐蚀产物进行分析,并分析出各腐蚀产物相对含量。结果 发现平行磁场的加入,加速了V型槽槽外的腐蚀,减缓了V型槽槽内的腐蚀。随着磁场强度的增加,平行磁场对V型槽槽外和槽内的促进及抑制作用加强,无磁场时V型槽槽外腐蚀产物为Fe₂O₃,然而随着磁场强度的增加,V型槽槽外腐蚀产物Fe₂O₃的相对含量增多,单质Fe的相对含量减少。而V型槽槽内的腐蚀产物Fe₂O₃随着磁场强度的增加逐渐减少,并且在40 mT时腐蚀产物变化为Fe₃O₄,70 mT时腐蚀产物变化为FeO。结论 平行磁场的存在加速了V型槽槽外腐蚀,抑制了V型槽槽内腐蚀,并随着磁场强度的增加,磁场对管线钢腐蚀的促进及抑制作用均增强。本...     

含硫酸盐还原菌海水中磁场强度对X100钢耐蚀性的影响

采用交流阻抗、动电位极化技术和腐蚀失重法研究了不同磁场强度下X100钢在接菌海水溶液中的腐蚀行为,并利用金相显微镜观察不同磁场强度下的表面腐蚀形貌。结果表明:磁场的存在对SRB的生长具有一定的抑制作用,且磁场强度越大,磁场对SRB生长的抑制作用越明显;电化学测试结果表明,与无磁场条件相比,外加磁场条件下SRB对X100钢的腐蚀作用减轻,且随着磁场强度的增加,电荷转移电阻(Rct)增大,腐蚀电流密度减小,腐蚀速率下降;腐蚀形貌结果表明,无磁场条件下的基体表面呈现较多大且深的腐蚀坑,而外加磁场条件下的试样表面腐蚀坑数目减少,且随着磁场强度越大,试样表面越平整。     

热带雨林环境中典型霉菌对PCB-HASL腐蚀行为的影响

目的探究热带雨林环境中典型霉菌作用下PCB-HASL的腐蚀机制。方法将PCB-HASL试样灭菌后放入机箱,置于西双版纳户外进行2年的暴露试验,经不同周期取回,分析观察试样表面腐蚀情况。将筛选出的典型霉菌孢子液喷洒在无菌试样上,置于湿热环境中,通过激光共聚焦显微镜(3D LSCM)、扫描电子显微镜(SEM)和能谱仪(EDS)分析试样表面形貌和成分,并观察霉菌的生长情况,使用电化学工作站及扫描开尔文探针(SKP)对PCB-HASL表面不同周期霉菌作用下的腐蚀电位进行分析。结果随着户外暴露周期的增加,PCB-HASL表面腐蚀面积逐渐增加,表面伏打电位先上升后下降。EDS能谱分析结果表明,腐蚀产物中主要含Sn 58.88%,O 30.93%,腐蚀产物主要为Sn的氧化物。木贼镰孢菌(Fusarium equiseti)和光轮层炭壳菌(Daldinia eschscholtzii)覆盖区域腐蚀程度严重,腐皮镰刀菌(Fusarium solani)菌丝生长旺盛,中期腐蚀电位明显降低,由-0.3 V降至-0.52 V。结论西双版纳热带雨林环境中对PCB-HASL腐蚀作用显著的典型霉菌为Fusarium equiseti、Daldinia eschscholtzii和Fusarium solani,在湿热环境下会造成PCB-HASL的腐蚀,其腐蚀机制主要为薄液膜下的电化学腐蚀。     

超高强钢在不同单一霉菌环境中的腐蚀行为研究

通过扫描电镜结合能谱分析,对Aermet100钢、300M钢和超高强不锈钢3种超高强钢在绳状青霉、黄曲霉和杂色曲霉3种单一菌种中的腐蚀形貌进行观察分析,结果表明：3种超高强钢试样进行84 d霉菌试验后,试样表面都发生一定的腐蚀。其中,在杂色曲霉环境中,3种超高强钢腐蚀都比较严重。采用扫描Kelvin探针测试技术,研究了3种超高强钢在杂色曲霉环境中的腐蚀行为,结果表明：杂色曲霉对Aermet100钢和300M钢的腐蚀行为有一定促进作用;而杂色曲霉形成的生物膜覆盖在超高强度不锈钢表面,抑制其腐蚀的发展。     

旋转磁场对海水中铜流动腐蚀的影响(英文)

通过实验室中12d的旋转电磁腐蚀实验,研究海水中铜的流动腐蚀。利用扫描电镜和X射线能量分散分析系统(SEM/EDAX)和X射线衍射仪(XRD)分析铜试样的表面微观结构和相组成,包括空干后腐蚀产物膜中的Cu2O和CuO的组成。结果表明:流动腐蚀过程是坑蚀、扩展、腐蚀产物膜和表面产物溶液,最后是坑蚀。旋转电磁场抑制了铜在海水中的流动腐蚀。     

磁场对铜在含三价铁离子硫酸溶液中的腐蚀行为的影响

采用电化学测量方法研究了磁场对铜在含三价铁离子硫酸溶液中自腐蚀以及阴极极化行为的作用,磁场不影响该体系的自腐蚀状态。磁场加速铜电极上三价铁离子的阴极扩散过程,随磁场强度增大,阴极极限扩散电流密度增大;磁场强度恒定时,磁场对三价铁离子阴极扩散的作用系数随三价铁离子浓度增加而增大;引起极限扩散电流密度明显增加的临界磁场强度随三价铁离子浓度增加而减小。由于铜与铁在含有三价铁离子的水溶液中的热力学稳定性不同,不同的自腐蚀电位下阴极反应的控制步骤类型不同而导致磁场作用不同。     

Effect of direct current electric field on atmospheric corrosion behavior of copper under thin electrolyte layer

A thin layer electrochemical cell was successfully developed to study the atmospheric corrosion behavior of copper film in printed circuit board (PCB-Cu) under thin electrolyte layer (TEL) and direct current electric field (DCEF) by electrochemical impedance and electrochemical noise analysis. The electrochemical measurements and SEM morphologies after corrosion test indicate that DCEF decreases the corrosion of PCB-Cu under TEL. The corrosion rate and probability of pitting corrosion of PCB-Cu under DCEF decrease due to the electric migration of aggressive Cl⁻ ion out of working electrode surface.     

The effects of temperature and electric field on atmospheric corrosion behaviour of PCB-Cu under absorbed thin electrolyte layer

The effects of temperature and electric field on atmospheric corrosion behaviour of PCB-Cu under absorbed thin electrolyte layers were investigated by cathodic polarization and electrochemical impedance spectroscopy. Results indicate that the cathodic current density increases with increasing temperature, but decreases with increasing intensity of electric field. Electric field reduces the corrosion rate of PCB-Cu due to the aggressive ions migrating out from PCB-Cu electrode surface under the effect of electric field. When the ions can not freely migrate out from PCB-Cu electrode surface, local enrichment of aggressive ions under the electric field will cause serious localized corrosion of PCB-Cu.     

薄层液膜下直流电场对铜的腐蚀行为、氯离子迁移行为和枝晶生长的影响(英文)

采用动电位极化和表面分析技术(SEM/EDS),研究薄层液膜下直流电场对印刷电路板铜的腐蚀行为、氯离子迁移行为和枝晶生长的影响。结果表明:直流电场使铜的腐蚀减弱;氯离子在直流电场作用下由负极到正极发生定向迁移,并且富集于电场的正极,导致电场正极发生严重的局部腐蚀;枝晶生长于电场的负极,并且其速率和尺寸随着外加电压的增加和暴露时间的延长而分别加快和变大。     

The effects of Cl ion concentration and relative humidity on atmospheric corrosion behaviour of PCB-Cu under adsorbed thin electrolyte layer

The effects of Cl⁻ ion concentration and relative humidity on atmospheric corrosion behaviour of PCB-Cu under adsorbed thin electrolyte layer were investigated by cathodic polarization curves and electrochemical impedance spectroscopy. Results indicated that the cathodic process of PCB-Cu corrosion was dominated by the reduction of oxygen and corrosion products. The cathodic current density increased with increasing relative humidity and Cl⁻ ion concentration. The corrosion rate was initially dominated by oxygen reduction, but at the later stage of corrosion, the anodic process began to affect the corrosion rate due to the accumulation of corrosion products.     

Effects of alternating magnetic field on the corrosion rate and corrosion products of copper

The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray (SEM/EDAX), and X-ray diffraction (XRD). The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl(OH)3, and FeCl3·6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.     

Influence of Static Low Electromagnetic Field on Copper Corrosion in the Presence of Multispecies Aerobic Bacteria

The effects of low electromagnetic field(EMF)( B = 2 mT) on the corrosion of pure copper in the absence and presence of multispecies marine aerobic bacteria were investigated in this work. The results showed that EMF has an inhibitory effect on copper metals and decreases the corrosion rate of copper metals in sterile artificial seawater. However, microbiologically influenced corrosion of Cu was increased in the presence of electromagnetic field due to its effect on the biofilm morphology and structure. EMF reduced the growth rate of bacteria and decreased bacterial attachment, thereby forming a heterogeneous and non-stable biofilm on the Cu surface in the presence of EMF. Moreover, the biofilm was dispersed throughout the surface after 7 days, whereas the scattered bacteria were observed on the surface after 10 days. Confocal laser scanning microscopy images showed large and deep pits on the surface in the presence of EMF and confirmed the acceleration of Cu corrosion in the presence of EMF and multispecies bacteria. Furthermore, XPS and FTIR results demonstrated that the corrosion products and metabolic by-products were significantly changed in the presence of EMF.