聚苯胺含量对镁合金上聚苯胺环氧涂层防腐性能的影响

在AZ31B镁合金表面制备了含本征态聚苯胺O%,1%,2%,4%,6%的聚苯胺/环氧防腐涂层,通过Tafel极化曲线、电化学阻抗谱测试及中性盐雾实验对比了其在3.5%NaCl溶液中的防腐性能.结果表明:聚苯胺的含量时聚苯胺环氧涂层的防腐性能有较大影响,聚苯胺的质量分数为2%时,涂层具有最佳的防腐性能.     

掺杂态和本征态聚苯胺对不锈钢的保护作用

用电化学方法在不锈钢表面制备了磷酸掺杂的聚苯胺,将掺杂态聚苯胺浸在1mol/L氨水中脱掺杂得到本征态聚苯胺。用扫描电子显微镜和红外光谱对掺杂态和本征态聚苯胺进行了表征,采用动电位极化曲线和电位-时间曲线研究了它们对不锈钢在1mol/L硫酸钠溶液中的保护性能。结果表明,掺杂态和本征态聚苯胺表面都有孔,使不锈钢的自腐蚀电位显著正移;本征态聚苯胺起机械隔离作用,掺杂态聚苯胺主要使不锈钢钝化;掺杂态聚苯胺对不锈钢的保护时间比本征态的长很多。     

本征态聚苯胺/环氧有机硅复合涂层的防腐性能

目的研究本征态聚苯胺/环氧有机硅复合涂层在Na Cl溶液中对Q235低碳钢的防腐效果。方法以自制的本征态聚苯胺为防腐颜料,按比例加入填料及助剂,砂磨分散后制备质量分数为0.5%、1.0%及1.5%的本征态聚苯胺/环氧有机硅复合涂层。Q235钢板经砂纸打磨后去油除渍,采用喷涂方式涂覆制备涂层样品。利用扫描电子显微镜观察不同添加量的本征态聚苯胺在环氧有机硅涂层中的分散状态,涂层在质量分数为3.5%的Na Cl溶液浸泡不同时间,采用X射线光谱分析涂层浸泡后的物相,并通过开路电位和电化学阻抗谱对比分析涂层的耐腐蚀性能。结果本征态聚苯胺/环氧有机硅复合涂层中EB添加量(质量分数)为1.0%时,颗粒分散较均匀且能促进形成致密的氧化钝化膜,浸泡后期的涂层表面微孔电阻值较高(Rpo=3.89×106Ω·cm2),表现出良好的电化学性能;添加量(质量分数)为0.5%时颗粒分散较稀疏,涂层的阻抗值和拟合电阻值均下降;添加量(质量分数)为1.5%时涂层的阻抗值和拟合电阻值较小,腐蚀速度不断加快。结论本征态聚苯胺添加量(质量分数)为1.0%时,其在环氧有机硅涂层的分散均匀且致密,并在3.5%的Na Cl溶液中浸泡后对Q235低碳钢表现出良好的防腐效果。     

聚苯胺纳米纤维超声合成及其防腐蚀性能

在超声场下用直接混合法合成了聚苯胺纳米纤维。将聚苯胺纳米纤维与环氧树脂共混浸涂于304不锈钢表面,研究涂层对不锈钢的的防腐蚀效果。结果表明,在3.5%NaCl和0.5 mol/L HCl溶液中,比较本征态聚苯胺/环氧树脂涂层,掺杂态聚苯胺/环氧树脂涂层具有较好的防腐蚀效果,环氧树脂涂层对304钢也有一定的防腐蚀效果。     

硅烷增强镁合金防腐有机涂层的研究

为了提高镁合金的耐腐蚀性能,结合硅烷处理和胶粘涂层技术在AZ31镁合金表面制备了环氧防腐涂层。通过扫描电镜对涂层表面形貌进行观察,采用划格法、浸泡法及盐雾试验等分析镁合金表面硅烷处理对有机涂层的附着力及耐蚀性的影响。研究结果表明：采用KH-550型硅烷进行处理后,镁合金基体与有机涂层之间形成化学键,涂层与基体结合牢固,附着力为1级,耐饱和盐水23d不起泡。硅烷处理明显提高了有机涂层对基体的附着力和耐蚀性,因此,硅烷＋胶粘涂层的方法可用于镁舍金的表面防腐。     

有机酸二次掺杂超疏水聚苯胺的制备及其耐蚀性

利用化学氧化法在硫酸体系中合成掺杂态聚苯胺,用氨水脱掺杂得到本征态聚苯胺,再采用对甲苯磺酸(TSA)、柠檬酸(CA)及十二烷基苯磺酸(DBSA)对本征态聚苯胺进行二次掺杂得到超疏水聚苯胺。通过傅里叶红外光谱(FTIR)、扫描电镜(SEM)等对聚苯胺进行了结构表征和形貌观察,通过电化学测试研究了在3.5%NaCl溶液中超疏水性聚苯胺的耐蚀性。结果表明:三种有机酸二次掺杂均能够有效提高聚苯胺的疏水性及耐蚀性,并且随着聚苯胺疏水性的增强,其对不锈钢的腐蚀防护效果提高;其中,TSA二次掺杂的聚苯胺的疏水性和耐蚀性最强。     

聚苯胺微乳液及其对水性防腐涂料防腐性能的影响

目的用不同酸掺杂的聚苯胺微乳液制备水性防腐涂料,提高马口铁表面涂层的耐腐蚀性能。方法采用扫描电子显微镜、傅立叶变换红外光谱和热重分析表征聚苯胺性能,通过动电位极化法及耐水性、耐盐雾和耐盐水实验检测聚苯胺微乳液水性防腐涂层的防腐性能,用铅笔硬度和划格法表征涂层的硬度和附着力。结果磷酸掺杂聚苯胺微乳液、本征态聚苯胺微乳液制备的水性防腐涂层都对马口铁起到良好保护作用。含有盐酸掺杂聚苯胺微乳液和不含聚苯胺微乳液的水性防腐涂层在浸泡过程中很快失去保护作用。掺杂态聚苯胺使马口铁表面钝化和屏蔽,本征态聚苯胺起机械屏蔽作用。通过把聚苯胺微乳液添加到水性防腐涂料中,发现涂层的硬度和附着力均没有发生明显下降,表明聚苯胺微乳液在水性防腐涂料中分散均匀,对涂层的性能影响较小。结论当水性防腐涂料中的聚苯胺质量分数为0.3%时,磷酸掺杂的聚苯胺微乳液具有最佳的耐腐蚀性能,其腐蚀电流密度Jcorr=7.359×10-7 A/cm2,腐蚀电位Ecorr=-0.527 V。     

基于聚苯胺的光固化防腐蚀涂层

利用十二烷基苯磺酸 (DBSA) 对本征态的聚苯胺 (PANI) 进行掺杂,将不同含量的掺杂后的聚苯胺分别加入到光固化树脂聚氨酯丙烯酸酯 (6071) 中,制备了一种低VOC排放的光固化聚苯胺防腐蚀涂层。通过实时红外以及漆膜性能的测试选择了合适的光引发剂,通过电化学阻抗谱、盐雾实验以及极化曲线对涂层的防腐蚀性能进行了测试。结果表明,加入0.4%DBSA-PANI的光固化涂层具有最佳的防腐蚀性能。     

不锈钢表面聚苯胺基复合涂层的制备与防腐蚀性能研究

目的 制备一种新型复合防腐涂层,增强316L不锈钢在中高温硫酸溶液中的耐蚀性.方法 首先使用化学氧化法在石墨(G)颗粒表面原位聚合聚苯胺(PANI),制得PANI/G复合材料,再使用环氧树脂(EP)作为粘结剂,制备PANI/G/EP复合涂层.对比了PANI/G/EP复合涂层与PANI/EP复合涂层及添加氧化石墨烯(GO...     

掺杂镍对镁合金表面冷喷涂锌基涂层性能的影响

目的研究镍添加对冷喷涂锌基涂层耐蚀性的影响,为镁合金提供有效的防护涂层。方法采用低压冷喷涂技术在镁合金基体表面分别制备锌基和锌/镍基复合涂层,通过微观观察、摩擦磨损实验、电化学极化法和电化学阻抗谱测试及全浸泡腐蚀试验,研究镁合金表面冷喷涂涂层的结构、摩擦磨损行为和耐蚀性。结果镁合金表面冷喷涂锌基涂层后,其硬度和耐磨性得到显著提高,掺镍后的锌/镍基涂层具有更高的硬度和耐磨性。锌基和锌/镍基涂层均能为镁合金提供腐蚀防护,锌/镍基涂层比锌基涂层具有更好的耐蚀性。相对镁合金来说,锌基涂层和锌/镍基涂层的自腐蚀电位分别正移了260 mV和560 mV;长期腐蚀后锌/镍基涂层形成了更致密的腐蚀产物膜,腐蚀电阻显著高于锌基涂层。结论冷喷涂锌基和锌/镍复合涂层均能对镁合金提供防护作用,掺杂镍后的锌/镍基复合涂层具有更高的硬度、耐磨性和耐蚀性。     

The effect of epoxy coating containing emeraldine base and hydrofluoric acid doped polyaniline on the corrosion protection of AZ91D magnesium alloy

Corrosion protection of epoxy coatings containing emeraldine base polyaniline (PANI) or hydrofluoric acid doped PANI on AZ91D magnesium alloy were studied by EIS and Pull-Off Adhesion Test. The results indicated that the addition of emeraldine base PANI or hydrofluoric acid doped PANI could improve the corrosion resistance of epoxy coating. The epoxy coating containing hydrofluoric acid doped PANI had the best performance of the corrosion protection among three systems under investigation. The corrosion product film was analyzed by XPS indicating that PANI changed the chemical structure of the corrosion film. The protective mechanism imparted by PANI was discussed.     

前处理工艺对镁合金钛/锆转化膜耐蚀性能的影响

研究了酸洗以及酸洗+碱洗前处理工艺对AZ91D镁合金无铬、无裂纹、低能耗钛/锆转化膜耐蚀性能的影响。结果表明,单独的酸洗前处理使得AZ91D镁合金表面的α相优先溶解,合金表面粗糙度增加,不利于钛/锆转化膜耐蚀性能的增加。合理地利用酸洗+碱洗调整AZ91D镁合金表面化学状态能够有效提高钛/锆化学转化膜的耐蚀性能。     

Electrodeposition of zinc on AZ91D magnesium alloy pre‐treated by stannate conversion coatings

A stannate chemical conversion process followed by an activation procedure was employed as the pre‐treatment process for AZ91D magnesium alloy substrate. Zn was electroplated onto the pre‐treated AZ91D magnesium alloy surface from pyrophosphate bath to improve the corrosion resistance and the solderability. The surface morphologies of conversion coating and zinc coating were examined with scanning electron microscope (SEM). The phase composition of conversion coating was investigated by X‐ray diffraction (XRD). The electrochemical corrosion behavior of the coatings in the corrosive solution was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that the activated stannate chemical conversion coating provided a suitable interface between zinc coating and the AZ91D magnesium alloy substrate. The corrosion resistance of the AZ91D substrate was improved by the zinc coating.     

Corrosion protection of Mg–5Li alloy with epoxy coatings containing polyaniline

The protective ability of epoxy coating containing polyaniline (PANI coating) on Mg–5Li alloy in 3.5% NaCl aqueous solution has been studied by means of EIS and electrochemical noise measurements (EN). The results of EN and EIS revealed that the PANI coating protected Mg–5Li alloy from corrosion perfectly. XPS results indicated that the presence of polyaniline changed the chemical structure of the corrosion film on the alloy surface. An analysis of the electrochemical noise data based on stochastic analysis indicated that the corrosion growth probability of Mg–5Li alloy beneath the coating was decreased by the addition of polyaniline.     

Electrodeposition and corrosion resistance of Ni–P–TiN composite coating on AZ91D magnesium alloy

In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were added to fabricate Ni–P–TiN composite coating by electrodeposition. The surface, cross-section morphology and composition were examined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicate that TiN nanoparticles were doped successfully in the Ni–P matrix after a series of complex pretreatments including activation, zinc immersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion between magnesium alloy and composite coating. The microhardness of the Ni–P coating increases dramatically by adding TiN nanoparticles and subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni–P–TiN composite coating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni–P coating in short immersion time. However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.     

A novel dual nickel coating on AZ91D magnesium alloy

Magnesium alloys covered with metal coating display excellent corrosion resistance,wear resistance,conductivity and electromagnetic shielding properties.The electroless plating Ni-P as bottom layer following the electroplating nickel as surface layer on AZ91D magnesium alloy was investigated.The coating surface morphology was observed with SEM and the structure was analyzed with XRD.Electrochemical tests and salt spray tests were carried out to study the corrosion resistance.The experimental results indi...     

AZ91 D 镁合金表面铈转化膜及环氧 / 氟碳涂层附着性研究

利用化学浸泡法在AZ91D镁合金表面制备铈盐转化膜,优化了铈盐转化处理工艺,研究了铈盐转化膜的微观形貌、组织结构及耐蚀性能。在转化膜表面分别涂覆环氧树脂和氟碳树脂涂层,测试了两种复合涂层的力学性能。结果表明:铈盐转化膜由双层膜组成,在优化的工艺条件下进行转化处理能够提高镁合金的耐腐蚀能力;铈盐转化膜对环氧树脂的适应性要优于氟碳树脂。     

AZ91D 镁合金表面 Ni-P / Ni-Sn-P 双镀层的制备与性能研究

目的提高AZ91D镁合金的耐腐蚀性能,扩大其应用范围。方法先在AZ91D镁合金表面化学镀Ni-P镀层,再化学镀Ni-Sn-P镀层,形成Ni-P/Ni-Sn-P双镀层。研究Ni-P/Ni-Sn-P双镀层的表面形貌和耐腐蚀性能,并与Ni-P单镀层进行对比。结果 Ni-P/Ni-Sn-P双镀层表面分布更均匀平整,缺陷较少,孔隙率较低,具有无定形结构。二次Ni-Sn-P镀层的腐蚀电位约为-0.77 V,略低于一次化学镀Ni-P层(约-0.68 V),两镀层间的电位差使得其构成了微腐蚀电偶,Ni-P层作为阴极,Ni-Sn-P层作为阳极,阳极优先被腐蚀。结论 Ni-P/Ni-Sn-P双镀层的Ni-Sn-P外层能为Ni-P内层提供阴极保护,较好地横向分散腐蚀电流,从而增强AZ91D镁合金基底的耐腐蚀性能。     

Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment

In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane‐based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X‐ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications.