《中国表面工程》2007年第2期

表面工程系统接触力学模型；用于材料表面改性的空气介质阻挡放电发射光谱研究；适用于渗碳齿轮齿面修复的激光熔覆铁基自强化合金及其性能研究；等离子体电解氧化过程中参数控制模式分析；氧化铝增强无机硅酸锌耐蚀抗磨涂层的研究     

空心微珠改性无机硅酸锌涂层的防护性能

用粉煤灰中提取的空心微珠对无机硅酸锌涂层进行改性,通过电化学测试和盐雾试验对比研究无机硅酸锌涂层改性前后的耐腐蚀性能,并利用扫描电镜观察涂层的微观结构。结果表明:经预处理后的空心微珠改善了涂层的耐腐蚀性能,空心微珠的加入显著提高了涂层的致密度。此外,在腐蚀过程中生成的腐蚀产物与涂层微孔结构结合良好,有效提高了腐蚀介质向涂层内部渗透的阻力,对基体起到了良好的保护作用。     

超细锌粉无机硅酸锌涂层的结构及耐蚀性研究

制备了3种超细锌粉作填料的无机硅酸锌涂层,用FTIR、SEM对涂层的固化机理和结构进行了研究,对3.5%NaCl溶液浸泡腐蚀后的试样表面形貌进行了观察,通过电化学试验研究了涂层的耐蚀性.结果表明,无机硅酸锌涂层的结构为:Zn粉颗粒间以Si-O-Zn聚合物网络键合,涂层与底材钢基体间是以化学键结合的微观多孔的涂层结构;涂层的耐蚀性随Zn粉颗粒度的减小而显著提高.涂层的耐蚀机理主要是电化学阴极保护作用以及腐蚀产物填塞涂层孔隙的物理屏蔽作用.     

填料对无机硅酸锌涂层耐腐蚀性能的影响

利用正交试验方法确定锌粉、磷铁粉和高岭土在水性无机硅酸锌涂层中的加入量,在不同条件下评价涂层的耐腐蚀性能,通过扫描电镜(SEM)和X射线衍射仪(XRD)分析了腐蚀产物的形貌和微观结构,采用电化学方法测试了涂层的极化曲线。结果表明:添加填料的无机硅酸锌涂层具有良好的耐腐蚀性,涂层抗腐蚀介质渗透的能力提高。涂层最佳成分配比为纯锌粉加入量为固相部分总质量的70%、磷铁粉为10%、高岭土为18%和膨润土为2%。相比纯锌粉涂层,其成本降低了近30%。     

硅丙乳液在鳞片状无机富锌涂料中的应用

利用硅丙乳液改性后基料与鳞片状锌粉均匀混合,制备硅酸锌系列水性无机富锌防腐涂料;并研究了涂料及其涂层的性能.结果表明,涂料中加入20 mass%的硅丙乳液改性后,基料对鳞片状锌粉有更好的润湿分散性,所得涂层的黏结力、耐水性、耐酸性、耐高温性、阴极保护作用均明显提高,改性涂层的耐蚀性良好,有应用价值.     

模数对水性硅酸钾富锌涂层电化学行为的影响

通过测量涂层腐蚀电位与涂层电化学交流阻抗,研究了水溶性K2SiO3溶液的模数(SiO2/K2O摩尔比)对水性无机富锌涂层电化学行为的影响.结果表明,水性无机富锌涂料随着水基模数的增加,涂层腐蚀电位增高,涂层对腐蚀介质的屏蔽性能增强,涂层中锌粉颗粒的活性溶解阻力增大.用扫描电子显微镜(SEM)观测不同模数水性无机富锌涂层的结构表明,水性无机富锌涂料水基模数的增加使涂层中锌粉颗粒之间充分交联,涂膜强度增大,涂层中锌粉颗粒之间的缝隙减小,涂层的致密性增强.     

钢铁构件表面上的无机富锌涂层

阐述了无机富锌涂层的研究、发展、特性和应用，指出无机富锌涂层具有杰出的耐环境侵蚀性能、耐化学性、耐溶剂性、耐辐射性、耐热性，在恶劣腐蚀环境下它是钢结构件的最佳底涂层。     

无机富锌涂层的诞生和应用

本文全面阐述了无机富锌涂层的研究、发展、特性和应用，指出无机富锌涂层具有杰出的耐环境侵蚀性、耐化学性、耐溶剂性、耐辐射性、耐热性，在恶劣腐蚀环境下它是钢结构件的最佳底涂层。     

无机富锌涂层的研究和发展

本文全面阐述了无机富锌涂层的研究、发展、特性和应用，指出无机富锌涂层具有杰出的耐环境侵蚀性能、耐化学性、耐溶剂性、耐辐射性和耐热性，在恶劣腐蚀环境下它是钢结构件的最佳底涂层。     

无机硅酸锌涂料在锅炉部件中的应用

无机硅酸锌涂料是一种双组分溶剂型无机富锌硅酸盐底漆，在干膜中锌的质量比超过80％，该涂料适用于桥梁、储罐、管道、钢结构等的保护。文章总结了这种涂料用于锅炉部件时的一些涂装工艺问题。     

Synergistic corrosion protection for galvanized steel by phosphating and sodium silicate post-sealing

To improve the corrosion resistance of phosphate coatings, the phosphated hot-dip galvanized (HDG) sheets were post-sealed with sodium silicate (water glass) solutions. The morphology and chemical composition of the composite coatings was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effect of sodium silicate post-sealing treatment on the corrosion behaviors of phosphate coatings was investigated by neutral spray salt (NSS) tests and electrochemical measurements. The results show that after the silicate post-treatment the pores among zinc phosphate crystals are sealed with the films containing Si, P, O and Zn, leading to the formation of the continuous composite coatings on the surface of HDG steel. The corrosion resistance of the composite coatings depending on concentration of sodium silicate and post-sealing time is greatly improved by the silicate post-treatment. The optimum concentration of silicate and post-sealing time are 5 g/L and 10 min, respectively. Both the anodic and cathodic processes of zinc corrosion on the samples are suppressed conspicuously, and the synergistic protection effect of the single phosphate coatings and the single silicate films is evident. Moreover, the low frequency inductive loop in electrochemical impedance spectroscopy (EIS) is disappeared and the electrochemical impedance values are increased for more than one order of magnitude. The corrosion protection of the composite coatings is comparable to that provided by the chromic acid post-treatment.     

Electrochemical behavior of organic and inorganic zinc-rich coatings in 3.5% NaCl solution

1　INTRODUCTIONZinc richcoatings (ZRP)havebeenusedformanyyearsinordertoprotectsteeleffectivelyinag gressiveatmospheres ,mainlyinmarineandindustrialenvironments,againstcorrosion .ItiscommonlyacceptedthattwofundamentalprotectionmechanismsoperateinZRP[13] :1)thegalvanicprotectionstage ,whichrequires goodelectricalcontactamongthezincparticlesthemselvesaswellasbetweenthemandthesteelsubstrate ;2 )thebarrier likebehaviorstage ,whichisreinforcedbytheamountandnatureofzinccorrosionproductslead ing…     

Formation and Surface Structural Features of Crystalline Ceramic Nanocomposite Coatings on Aluminium Using Lithium Sulphate with Silicate Additive

We have synthesized a series of the ceramic coatings by anodization of aluminium using lithium sulphate and sodium silicate additive.Our experiments show that the present coatings are nanocomposites in nature,consisting of a mixture of nanocrystalline alumina,silica,aluminium silicate and mullite; the formation of alumina was similar to conventional anodizing technology,while the formation of mullite was attributed to an addition of sodium silicate.The microhardness of the coatings progressively increased with the increasing current density up to 0.2 A/cm2,which could mainly be attributed to the decrease of porosity in the interfacial region of the oxides up to the range.From the performance of the coatings against corrosion(Tafel/Nyquist plots),it was inferred that the coatings fabricated by lithium sulphate–sodium silicate bath have enhanced corrosion resistance(Rp=3.12 kΩ),as well as better microhardness value than that of the lithium sulphate bath alone(Rp=660.96 Ω) which confirm the perception that the silica particles included in the anodized alumina matrices randomly.Presence of Al,Si and O indicated that the electrolyte components had been intensively incorporated into the coatings.     

Effect of SiO2:Na2O molar ratio of sodium silicate on the corrosion resistance of silicate conversion coatings

Passivation treatment by sodium silicate solution is considered as an alternative to chromium chemical conversion treatment to improve the corrosion resistance of hot-dip galvanized (HDG) steels. In this paper, a transparent silicate coating was formed on the surface of HDG steel by immersing in sodium silicate solution with SiO₂:Na₂O molar ratio in the range from 1.00 to 4.00. The parameter about the SiO₂:Na₂O molar ratio of silicate solution has been discussed using corrosion resistance and surface morphology. Tafel polarization, electrochemical impedance spectroscopy (EIS) measurements and neutral salt spray (NSS) test show that silicate coatings increase the corrosion resistance of HDG steels. From the results obtained, it is deduced that the optimum SiO₂:Na₂O molar ratio is 3.50. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis (XRD), and reflectance absorption infrared spectroscopy (RA-IR) show that there are no obvious differences of the chemical composition and structure in various silicate coatings. The silicate coatings mainly consist of zinc oxides/hydroxides, zinc silicate and SiO₂. However, atomic force microscopy (AFM) images reveal that the surface of silicate coatings with a molar ratio of 3.50 is more compact and uniform than other silicate coatings.     

Innenschutz von Lagerbehältern für Heizöle und ähnliche Medien mit Zinksilikaten

Internal protection of storage tanks for fuel oil and similar media by zinc silicates The internal surfaces of storage tanks for fuel oils or motor fuels must be protected against corrosion by such media (cause: type and pollution of the stored medium) and against rust formation (by reaction with condensed water and oxygen) by coatings (with silicate or plastic based coating materials) or linings (foils or inserted plastic bags). At the present time zinc silicate appears to be the most favourable type of internal tank coating material, having the widest range of applications and the lowest susceptibility to failure.     

The performance of a waterborne zinc-rich coating from sodium silicate solution catalyzed by ammonium acetate

Through general property tests, rheological measurements, SEM observations and weight changes after immersion, electrochemical methods and water vapor transmission tests, a waterborne zinc-rich coating from sodium silicate solution catalyzed by ammonium acetate was characterized. Results showed that the formula catalyzed by ammonium acetate overcame the poor water resistance of other non-catalyzed coatings, while binding the zinc powder in the film. The zinc-rich film had the basic features required for a zinc-rich primer to be useful and was electrochemically cathodically protective during tests. The acetate anion from ammonium acetate resulted not only in little early corrosion while catalyzing the formation of zinc silicate before cure but also stronger corrosion protection during the immersion test on the cured film. The velocity of water vapor transmission and the amount of acetate anions present decreased with time until a stable value was achieved after approximately 6 days.     

Novel zinc‐rich epoxy paint coatings with hydrated alumina and carbon nanotubes supported polypyrrole for corrosion protection of low carbon steel: Part II: Corrosion prevention behavior of the hybrid paint coatings

Utilization of various types of multi‐walled carbon nanotubes (MWCNTs) in zinc‐rich paints (ZRPs) is presented addressing percolation and porosity related phenomena of traditional ZRPs. Hybrid paint coatings were formulated with 3.21 wt% polypyrrole (PPy) deposited alumina‐MWCNT inhibitor particles (PDAMIPs) and 70 wt% zinc contents. Corrosion protection behavior of the hybrid coatings was investigated by electrochemical impedance spectroscopy (EIS), glow‐discharge optical emission spectroscopy (GD OES), X‐ray photoelectron spectroscopy (XPS), and FT‐Raman spectroscopy. Immersion and salt‐spray chamber tests gave evidence of improved galvanic protection and barrier nature of the hybrid coatings over the conventional ZRPs, whereas inhibited zinc corrosion and ignorable steel corrosion took place besides lower degradation of the binder. Zinc‐rich hybrid paints with either high relative amount of polyelectrolyte‐modified or low proportion of functionalized MWCNTs afforded enhanced corrosion prevention. This result is partly attributed to the nanotube volume fractions around the threshold of infinite cluster formation contributing to electrical percolation and galvanic action of the hybrids. Experimental results are discussed in a broader context on the basis of structure related findings of the PDAMIPs (described in Part I) and in the light of recent literature data. From the newly developed inhibitor particles, some of them are respected as worthy additives for application in hybrid coatings featuring high performance corrosion prevention functionality.     

硅酸铝短纤维增强AZ91复合材料的制备

以晶化的硅酸铝短纤维为增强体，以偏磷酸铝为粘结剂，把干法和湿法结合起来制做预制块，采用挤压浸渗工艺制备AZ91镁基复合材料，结合光学显微镜和扫描电镜进行铸造缺陷和显微组织分析。结果表明，中性的磷酸铝溶液是制备硅酸铝短纤维增强镁基复合材料（Al2O3-SiO2/AZ91）的最合适的预制块用粘结剂之一；采用复合挤压工艺可以有效防止或减轻金属基复合材料的组织缩松。     

Corrosion study of Ni/Zn compositionally modulated multilayer coatings using electrochemical impedance spectroscopy

Ni/Zn compositionally modulated multilayer (CMM) coatings were deposited using dual bath technique. Coatings corrosion performance was evaluated using electrochemical impedance spectroscopy (EIS) during extended immersion times up to 48 h. The results of electrochemical impedance spectroscopy showed that Ni/Zn CMM coatings had better corrosion resistance compared to that of the zinc single layer coating. The modified corrosion product which is formed on the Ni/Zn CMM coatings during extended exposure times and also a good barrier effect of the nickel layer against aggressive species in these coatings can be two important reasons for high corrosion performance and so protection performance of the Ni/Zn CMM coatings.