共查询到19条相似文献,搜索用时 187 毫秒
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为进一步研究Q235钢表面环氧粉末涂层在海洋环境中的失效机制,利用称重法研究了60℃下不同浓度的Na Cl溶液中水在不同阴极保护条件下的环氧粉末涂层中的扩散行为,利用电化学阻抗谱技术(EIS)研究了不同Na Cl溶液浓度和阴极保护水平对涂层性能的影响。结果表明:随Na Cl溶液浓度增加,涂层的饱和吸水量减少,水在涂层中的扩散系数变大,其扩散机制符合Fick扩散模型;Na Cl溶液浓度增加加速了环氧粉末涂层的劣化,阴极保护一定程度上也降低了环氧粉末涂层的性能,过保护则会明显影响涂层性能,涂层起泡过程中涂层电容经历明显的3个阶段,在第3阶段中涂层结构可能发生变化,直至涂层起泡失效。 相似文献
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滚动接触条件下铁基涂层的疲劳磨损寿命实验研究 总被引:1,自引:0,他引:1
利用超音速等离子喷涂技术在45钢表面制备了铁基合金涂层,利用球盘式疲劳磨损实验机评价了铁基涂层在两种载荷条件下的疲劳磨损性能,利用两参数Weibull分布表征了涂层的疲劳寿命,采用扫描电子显微镜(SEM)分析了涂层的微观结构和失效形貌,利用有限元方法研究了涂层内部应力分布.实验结果表明,载荷条件可以显著地影响涂层的寿命和失效形貌,高载下涂层的寿命明显降低;随着载荷的增加,主要失效形式由表面磨损失效转换成剥层失效,其中表面磨损是由于粗糙接触引起,而剥层则与应力分布机制有关. 相似文献
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涂层缺陷对涂层失效与基体腐蚀行为的影响研究 总被引:8,自引:0,他引:8
通过对涂层缺陷、涂层起泡、湿附着力等研究领域的回顾,讨论了涂层缺陷对腐蚀性介质离子在涂层中的传输行为、涂层失效、基体腐蚀行为等方面的影响。在此基础上,针对涂层缺陷研究现状中存在的一些未解决问题,提出了诸如计算机支持技术等可能的解决方法。 相似文献
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评述了有机涂层失效机理的现代研究方法,将电化学测试技术与现代表面分析技术和传统的涂料检测技术相结合,应用于涂层失效机理分析和寿命评估中.探讨了电化学交流阻抗谱技术在研究变海水压力作用下潜艇表面有机涂层的失效机理。以及建立腐蚀性介质渗入与涂层失效之间数学模型的可能性. 相似文献
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蒙脱土/聚丙烯酰胺复合涂层导水纤维的制备及性能 总被引:1,自引:0,他引:1
用钠基蒙脱土/聚丙烯酰胺及有机蒙脱土/聚丙烯酰胺两种复合涂层材料,对天然纤维进行涂层化处理,制备了两种蒙脱土/聚丙烯酰胺复合涂层导水纤维.用快速水分测定法研究了导水纤维在不同温度和土壤湿度时的动态导水规律.利用扫描电镜观察了涂层纤维的表面形貌及涂层材料在不同水势下的微观形貌.采用X射线衍射仪及比表面积与孔径分布测定仪对普通蒙脱土与有机蒙脱土的物理结构进行表征.实验表明涂层导水纤维具有基于土壤温度及湿度的自调节机制,以便保证植物生长的合理土壤湿度.对蒙脱土进行有机化处理后,其层间距及孔径增大,有利于水分的传导. 相似文献
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A batch of notebook personal computer components was manufactured from AZ91D Mg alloy by precision die-casting, subsequent chemical conversion and organic coatings. After storage for some time, some blisters were found on some components. SEM/EDS and FTIR analysis showed the blistering initiated because of in situ loss of adhesion at the organic coating/substrate interface, caused by contamination and/or corrosion. Data from accelerated environmental tests on deliberately contaminated model samples suggested that the blisters originated from contamination at the interface, and that the blistering was also related to the storage conditions. An empty blister forms at early time, and it gets filled with corrosion products later on, and corrosion further on, progress on these sports. An effective way to reduce blister formation is to avoid direct physical contact with all components in this product. 相似文献
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污水罐的腐蚀原因及其防护措施 总被引:1,自引:0,他引:1
炼油厂污水因为含有Cl-,NH3,CN-,S2-和酚类等强腐蚀介质,短时间内就能致使污水罐常规防腐蚀涂层起泡、剥落失效,最终导致罐体穿孔泄露.经现场多种涂料挂片试验筛选,采用WF40含硫污水介质专用防腐蚀涂料对腐蚀介质有很好的防护作用,从2004年使用至今,罐体运行正常,使用效果良好. 相似文献
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有机涂层的现代研究方法 总被引:19,自引:0,他引:19
本文介绍了有机涂层/金属体系性能与失效过程的研究和评价方法。电化学方法中电化学阻抗谱(EIS)技术是目前最主要的研究方法之一,同时一些新的技术(如局部电化学阻抗(LEIS)、扫描Kelvin探针(SKP)技术等)正在成为研究涂层体系性能的重要手段。一些非电化学方法的使用对研究和评价涂层性能与失效过程起到了补充的作用。除此,本文还简要介绍了涂层中水传输研究的两种模型,以期对水传输机理的认识得到更深入的了解。 相似文献
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Unlike metals, where failure analysis and life assessment methods are quite established, the failure analysis and life assessment
of coatings are often underrated and disregarded. This research encourages failure analysts to realize and avail the opportunity
provided by an alternative approach. The authors use energy density mechanics concepts to develop a new parameter in coating
blistering. A mixed mode stress intensity factor is used as a basis for the derivation. This new parameter will be useful
for the researchers and practitioners engaged in coating life assessment. It is recommended that the assessor combines field-determined
adhesion strength values and blister evaluation, together with laboratory-derived strain energy density data, to quantitatively
predict remaining coating life. This approach also provides a tool in failure analysis. 相似文献
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介绍了丙烷脱沥青装置--丙烷溶剂罐检测过程中发现的鼓泡开裂情况,通过金相组织分析,确定低合金高强度16MnR钢的鼓泡开裂原因是设备在工艺介质H2S含量超标情况下发生了典型的湿硫化氢环境下的氢鼓泡(HB)、氢致开裂(HIC)和应力导向氢致开裂(SOHIC),并从设备选材、工艺防腐蚀、设备防腐蚀等方面提出了改进措施. 相似文献
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This paper contains a review of the most vital concepts regarding the analysis and design of film systems. Various techniques have been presented to analyse and predict the failure of films for all common types of failure: fracture, delamination, general yield, cathodic blistering, erosive and corrosive wear in both organic and inorganic films. Interfacial fracture or delamination is the loss of bonding strength of film from substrate, and is normally analysed based on the fracture mechanics concepts of bi-material systems. Therefore, keeping the focus of this review on bonding strength, the emphasis will be on the interfacial cracking of films and the corresponding stresses responsible for driving the delamination process. The bi-material characteristics of film systems make the nature of interfacial cracks as mixed mode, with cracks exhibiting various complex patterns such as telephone cord blisters. Such interfacial fracture phenomenon has been widely studied by using fracture mechanics based applicable analysis to model and predict the fracture strength of interface in film systems. The incorporation of interfacial fracture mechanics concepts with the thermodynamics/diffusion concepts further leads to the development of corrosive degradation theories of film systems such as cathodic blistering. This review presents suggestions for improvements in existing analysis techniques to overcome some of limitations in film failure modelling. This comprehensive review will help researchers, scientists, and academics to understand, develop and improve the existing models and methods of film-substrate systems. 相似文献
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炼油厂污水含有c1-,NH3,,CN-,S^2-和酚类等强腐蚀性介质,致使污水罐常规防腐蚀涂层短时间内起泡、剥落失效,最终导致罐体穿孔泄露。根据污水罐具体腐蚀情况,使用电弧喷涂锌层与传统防腐蚀涂料涂层相结合形成复合防腐蚀涂层,获得了较好的防腐蚀效果,延长了污水罐防腐蚀周期。 相似文献
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目前有关绢云母对近红外吸收涂层自然老化性能的影响鲜见研究报道。采用绢云母改性聚氨酯(PU)/Sm_2O_3复合涂层,从涂层微结构、近红外吸收性能和力学性能角度系统研究了改性前后涂层经4个月自然老化后性能的变化规律。结果表明:改性前后涂层的微结构对自然老化均具有良好的稳定性,随自然老化时间的延长并未出现开裂、起泡、粉化等现象。改性后涂层在同等自然老化条件下对1.06μm近红外光的反射率要明显低于未改性涂层。改性前后涂层的硬度对自然老化具有良好的稳定性;未改性涂层的附着力、耐冲击强度及柔韧性受自然老化影响明显,但经绢云母改性后可得到明显加强,经自然老化4个月后仍然可达到1级、500 N·cm及3 mm。 相似文献