铈对化学沉积Co-Ni-B合金镀层结构的影响

研究了稀土Ce对化学镀Co-Ni-B合金层组织结构的影响。采用X-射线衍射仪、电感耦合等离子发射光谱仪、透射电镜和原子力显微镜考察了合金镀层的成分、结构和表面形貌。结果表明:随着镀液里Ce添加量的增加,合金镀层中的Co、Ni、Ce含量升高,B含量降低。化学镀Co-Ni-B合金层的结构由非晶态转变为微晶态。化学镀Co-Ni-B合金镀层表面由圆锥峰构成,较为平整;添加稀土Ce后,镀层变得凹凸不平。     

玻璃表面化学镀Co-Ni-P合金的研究

实验研究了玻璃基体表面化学镀Co-Ni-P合金的工艺过程和操作方法.讨论了镀液pH值及其他因素对镀层质量的影响.并对玻璃镀件进行了电镜扫描、X射线衍射、结合力和耐腐蚀性检测.实验结果表明:玻璃基体经过预处理、敏化及活化处理.镀液条件控制在80℃、pH为6、施镀时间40min进行化学镀合金,可以得到结合力较强、质量较好的Co-Ni-P合金镀层.     

铈对化学镀Co-Ni-P合金工艺的影响

研究了稀土元素铈对化学镀Co-Ni-P合金工艺的影响，在正交试验的基础上分析了镀液组成对沉积速度的影响，综合考察了镀层表面质量及镀层与基体的结合力，结果表明化学镀Co-Ni-P合金的工艺中，当稀土元素铈加入时，镀液的稳定性，沉积速度和镀层质量能明显提高，并由此得出工艺的最佳佳镀液组成和操作条件。     

钨对化学镀Ni-W-P合金镀层结构及性能的影响

通过不同的化学镀工艺配方,获得了4种不同钨含量的化学镀Ni-W-P三元合金镀层.研究了钨含量对镀层结构、硬度及在5%H2SO4溶液中耐蚀性的影响规律.研究发现,化学镀Ni-W-P三元合金镀层的结构受镀层中钨含量的影响较大,非晶态Ni-W-P三元合金镀层所需磷含量较非晶态Ni-P二元镀层所需磷含量要低,并且钨含量越高,所需磷含量越少;镀层硬度随镀层结构从非晶态→混晶态→纳米晶态转变而增加;镀层的耐蚀性随镀层中钨含量增加而变好,且非晶态镀层较混晶态和纳米晶态镀层更易形成钝化区.     

超声波下化学镀Co-Ni-P合金工艺的研究

将超声波引入Co-Ni-P合金的化学镀中,讨论了超声波功率、超声波频率、主盐、还原剂、配位剂、温度及pH值对化学镀Co-Ni-P合金沉积速率的影响。超声波的介入提高了沉积速率,功率较大时镀液的稳定性下降。通过分析工艺,得出了超声波下化学镀Co-Ni-P合金的最佳工艺。     

化学镀Ni-Sn-P合金的研究进展

介绍了近年来国内外在化学镀Ni-Sn-P合金镀层方面的研究进展,探讨了镍盐含量、锡盐含量、还原剂含量、络合剂含量、温度和pH等因素对化学镀Ni-Sn-P合金的镀速及镀层质量的影响。分析了镀层的表面形貌、结构及性能,概述了化学镀Ni-Sn-P合金镀层的应用及目前所存在的问题。     

十六烷基三甲基溴化铵对化学镀Co-Ni-P的影响

通过正交试验得到化学镀Co-Ni-P的优化基础配方(g.L-1)和施镀条件:CoSO4.7H2O为16、NiSO4.6H2O为9、NaH2PO2.H2O为30、Na3C6H5O7.2H2O为60、(NH4)2SO4为70,于pH=10、80℃施镀1 h;研究了阳离子表面活性剂十六烷基三甲基溴化铵对Co-Ni-P镀层成分以及镀层与基体结合力的影响。实验结果表明,在优化的基础配方中加入30 mg.L-1的十六烷基三甲基溴化铵,镀液稳定性好,沉积速率加快,镀层表面光亮,镀层与基体的结合力增强,镀层中钴含量增加,镍、磷含量降低,镀层的性能得到了很大的改善。     

化学镀Co-B-Y合金的电化学特性和组织结构的研究

测定和研究了引入稀土金属Y时化学镀Co-B合金镀液的阴极极化曲线、沉积速度、Co-B合金镀层的化学成分和晶体结构。结果表明稀土金属Y的介入明显地改善了化学镀Co-B合金的静止电位和极化度,随镀液里稀土金属Y添加量的增加,合金的沉积速度和镀层中Y的含量都是先增后降,且都在Y=4．0g／L时达到最大值。稀土Y的介入使化学镀Co-B-Y合金镀层中B的含量减少,Co含量增加,并使具有非晶态结构的化学镀Co-B合金转化为晶态结构的化学镀Co-B-Y合金。     

化学镀Ni-Fe-B-La合金工艺的研究

研究了稀土元素La介入化学镀Ni-Fe-B合金的镀覆工艺.在正交试验的基础上获得了化学镀Ni-Fe-B-La合金的基础配方,分析了加入稀土元素La后化学镀液中各种组分对镀层沉积速率的影响,并考察了镀液稳定性和镀层质量.通过稀土元素La的介入,Ni-Fe-B-La合金镀液稳定性和镀层的质量得到明显的改善;但随La含量的增加,沉积速率达到最大值后有降低趋势.     

化学镀Co-B合金(Ⅱ)

纳米晶合金具有独特的物理性能.通过化学镀方法获得纳米晶Co-B合金,分别研究了沉积层厚度和热处理温度对其矫顽力和比饱和磁化强度的影响.结果表明,开始阶段,随着镀层厚度的增加,矫顽力逐渐减小,而当镀层厚度大于0.6 μm时,矫顽力随镀层厚度的增加而逐步升高;比饱和磁化强度则始终随镀层厚度增加呈上升趋势.开始阶段,随着热处理温度的上升,矫顽力上升,当热处理温度高于450℃时,矫顽力开始减小;热处理温度对比饱和磁化强度影响较为复杂.     

Effect of cerium concentration on microstructure,morphology and corrosion resistance of cerium–silica hybrid coatings on magnesium alloy AZ91D

The aim of this work was to investigate the effect of cerium concentration on microstructure, morphology and anticorrosion performance of cerium–silica hybrid coatings on magnesium alloy AZ91D. Vinyltriethoxysilane (VETO) and γ-glycidoxypropyltrimethoxysilane (GPTMS) were employed as precursors to prepare sol–gel based silica coating. Cerium nitrate hexahydrate as dopant in five different concentrations was added into the silica coatings. Fourier transform infrared (FT-IR) spectrum analysis, viscosity measurements and scanning electron microscopy (SEM) were employed to characterize the microstructure and morphology of these coatings. It was found that with the increase of cerium concentration, the degree of decomposition of silane chains in the coating network increased. The corrosion resistance of the cerium–silica hybrid coatings was estimated by electrochemical impedance spectroscopy (EIS) measurements and potentiodynamic polarization tests. The results demonstrated that corrosion resistance of coatings initially increases and then decreases as cerium concentration goes up. When the cerium concentration is 0.01 M, corrosion resistance reaches its maximum.     

铝合金铈盐转化膜的研究

提出了一种铝合金铈盐化学转化成膜工艺,利用电化学方法研究了铝合金铈盐化学转化膜的成膜过程及耐蚀性能,结果表明,成膜促进剂的加入能有效提高铈盐转化膜的成膜速度,所得转化膜对铝合金的点蚀有较好的抑制作用。     

Screening study of spray solution parameters for depositing cerium-based conversion coatings on Al alloy 2024-T3

Cerium-based conversion coatings were deposited on aluminum alloy 2024-T3 by a spray process using a solution containing cerium chloride, hydrogen peroxide, and gelatin. As deposited coatings were composed of hydrated cerium oxide and were post-treated in a phosphate solution to improve corrosion performance. Coating solution parameters, including the pH (1–2.5), cerium chloride concentration (0.025–0.125 M), and hydrogen peroxide content (0–1.2 M), were varied to investigate the effect(s) of solution parameters on the corrosion performance of the post-treated coatings. Results indicated that thickness of coatings deposited from solutions with different pH values were similar, while coating thickness increased with increasing concentration of cerium chloride and hydrogen peroxide in the solutions. Electrochemical impedance spectroscopy and observations of the surface appearances of the coatings indicated that coatings deposited from solutions with a pH 2, a cerium concentration of 0.1 M, and a hydrogen peroxide concentration of 0.8 M exhibited the best corrosion resistance.     

Electrospun protective self‐healing coatings for light alloys: A better understanding of the intrinsic potential of the technology

Polymeric coating systems exhibit high potentiality to provide an effective barrier against corrosion of metallic surfaces. However, these coatings can lose their protective characteristics because of their high susceptibility to damage. Thus, the addition of corrosion inhibitors is desirable and considered as an alternative route for active corrosion protection. In the present work, eco‐friendly electrospun coatings of poly(vinyl alcohol) (PVA) loaded with cerium salts have been deposited onto aluminium 6082 alloy. Two different precursors of cerium (III) (i.e., cerium nitrate and cerium acetylacetonate) were added to the electrospinning solutions and the effectiveness of the resulting nanofibrous coatings was evaluated for the healing of generated defects. The microstructural features of the electrospun coatings have been investigated by scanning electron microscopy, infraredspectroscopy, and thermal analysis. Tensile tests were performed to assess the mechanical properties of the different fibrous coatings. The electrochemical behavior of both intact and damaged coatings was evaluated in 3 wt % NaCl solution by means of electrochemical impedance spectroscopy. All the deposited PVA coatings loaded with cerium(III) salts showed remarkable corrosion resistance. In the case of artificially damaged coatings, a self‐healing effect, which stops the development of the corrosion process and provides a significant recovery of the corrosion resistance, has been observed only for coatings loaded with cerium III acetylacetonate. The release of cerium from damaged PVA fibers has been demonstrated by means of inductively coupled plasma mass spectrometry. The observed self‐healing effect has been ascribed to the formation of cerium hydroxide on the defective zone, which hindered the corrosion process. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42728.     

铝合金表面电解沉积稀土转化膜工艺研究

研究了一种通过电解沉积方法在防锈铝LF21表面上生成铈盐转化膜的工艺,应用正交实验研究了有关因素对成膜过程的影响并获得了最佳的技术参数用极化曲线、交流阻抗和中性盐雾试验等方法测试了该工艺形成膜层的耐蚀性能及其组成一结果表明：经过电解沉积稀土转化膜处理后,防锈铝的阳极腐蚀过程受到了阻滞,自然腐蚀电位负移;与经过化学转化膜处理后相比,其耐蚀性能有显著提高,可通过400h的中性盐雾实验,亲水性能亦有明显提高。     

铝合金表面钒酸铈改性环氧涂层的制备与性能研究

通过水热合成法制备钒酸铈(CeVO4)纳米填料,将CeVO4分散到环氧树脂中获得改性涂层.分别涂覆在打磨后碱洗处理铝合金和直接喷砂处理铝合金上.采用XRD、FT-IR和SEM对CeVO4粉体进行表征,并通过附着力测试、电化学阻抗和长期浸泡实验对改性前后的涂层进行研究.结果表明:利用水热合成法可成功制备CeVO4纳米填料...     

Influence of the doping agent on the corrosion protection properties of polypyrrole grown on aluminium alloy 2024-T3

The corrosion protection properties of polypyrrole (PPy) electrodeposited onto aluminium alloy 2024-T3 substrates were investigated as a function of the doping agent. We used camphor sulfonic acid (CSA), para toluene sulfonic acid (p-TSA), phenylphosphonic acid (PPA), oxalic acid (OA) and cerium nitrate salt (Ce(NO₃)₃) as doping agents. The resulting coatings have been evaluated towards corrosion protection of aluminium alloy 2024-T3 using electrochemical impedance spectroscopy (EIS). Complementary, scanning electron microscopy (SEM) provided images on the morphology and the thickness of the coatings. The results showed that coatings formed using Ce(NO₃)₃ solution protect the substrate more efficiently compared to the other coatings.     

Effective corrosion protection of AA6061 aluminum alloy by sputtered Al-Ce coatings

Al-Ce coatings were deposited on silicon and AA6061 aluminum alloy substrates by DC magnetron sputtering using aluminum in combination with pure cerium targets. The materials were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and electrochemical impedance spectroscopy (EIS) in order to consider their application as high corrosion resistance coatings. The corrosion behavior of the films was studied using a NaCl aqueous solution (3.5 wt%). As for the characterization results, an apparent amorphous phase of aluminum oxide with small cerium compounds embedded in the matrix was detected by the X-ray diffraction patterns and HRTEM on the deposited films at 200 W and 4 Pa. At these conditions, AFM and SEM images evidenced crack-free coatings with low-roughness nanometric structures and columnar growth. EIS and Tafel results converged to indicate an inhibition of the corrosion reactions. The film displayed good stability in the aggressive medium and after 1 day of exposure underwent very little degradation. The variations in the impedance and Tafel characteristics were found to occur as a function of cerium content, which provokes important changes in the film protective properties.     

Cerium-doped hydroxyapatite/collagen coatings on titanium for bone implants

The novelty of the present research consists in the possibility of obtaining cerium-doped hydroxyapatite/collagen coatings on the titanium support, to improve the performance of the bone implants. These coatings were deposited on the titanium surface by biomimetic method using a modified supersaturated calcification solution (SCS) additionally containing a cerium source and collagen. Prior to the deposition of the apatite layer, an alkali ÷ thermal oxidation pretreatment has been applied to ensure an increase in the bioactivity of the titanium surface. The coatings were examined by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The EDX and XRD investigations of the coatings indicated that cerium was incorporated in the hydroxyapatite lattice. The collagen presence in the coatings was confirmed by FTIR analysis. The cerium-doped hydroxyapatite/collagen coatings showed good antibacterial efficacy against Escherichia coli and Staphylococcus aureus bacteria, being more effective against Escherichia coli. These coatings have a significant potential to be used in the dental and orthopedic implants, as the osseointegration depends on much more factors than simple formation of hydroxyapatite.     

Synergistic Effects of Montmorillonite/Cerium Nitrate Additives on the Corrosion Performance of Epoxy-Clay Nanocomposite Coatings

In this work, different amounts of montmorillonite were added to cerium nitrate epoxy mixture. Nanocomposite coatings containing cerium nitrate were applied on cold rolled steel panels. The state of dispersion and incorporation were characterized by transmission electron microscopy and atomic force microscopy. To investigate anticorrosive properties of nanocomposites, electrochemical impedance spectroscopy, polarization measurement and salt spray tests were employed. Results showed that epoxy cerium nanocomposite coatings were superior to the neat epoxy in corrosion protection properties. Also, it was observed that the best corrosion protection was achieved with nanocomposite coatings containing 4 wt.% and 2 wt.% cerium nitrate.