Ni-TiO2基纳米复合电刷镀层微观结构及腐蚀电化学行为

研究了用电刷镀在Q235钢上制备出Ni-TiO2纳米复合镀层复合镀液中,纳米颗粒的加入量及不同的表面活性剂对镀层性能的影响。采用SEM对复合镀层的表面形貌进行分析,用极化曲线研究了纳米复合镀层在NaCl溶液中的腐蚀电化学行为,结果表明:与纯Ni镀层相比,Ni-TiO2纳米复合镀层晶粒更加细小,空隙率更低,阳离子表面活性剂分散镀液所得镀层效果最为显著;复合镀液中纳米TiO2质量浓度为10g/L时,复合镀层的耐腐蚀性能最优;纳米颗粒含量相等的情况下,阳离子表面活性剂分散镀液所得镀层具有最好的耐腐蚀性能。     

镍基纳米氧化铝化学复合镀研究

研究了镍-磷-纳米Al2O3复合镀层的制备；用正交试验研究了纳米氧化铝、络合剂、分散剂、表面活性剂、添加剂、镀液pH、分散方式等诸因素对镀液性能和复合镀层质量的影响；得到纳米化学复合镀镀液的最佳组成。     

表面活性剂对镍-磷-纳米氧化铝复合镀的影响

研究了阴离子型表面活性剂(十二烷基苯磺酸钠、十二烷基硫酸钠)和阳离子型表面活性剂(三乙醇胺)对镍-磷-纳米氧化铝复合镀性能的影响.讨论了表面活性剂的种类、加入量对沉积速度、镀层的硬度和耐磨性能的影响.通过扫描电镜(SEM)观察各种复合镀层形貌,利用能谱仪(EDS)测量镀层中纳米A l2O3粒子的复合量.结果表明:纳米复合化学镀液中两种阴离子型表面活性剂的较佳加入量均为50 mg/L,阳离子型表面活性剂较佳加入量为100mg/L;采用阳离子表面活性剂时所得镀层的纳米粒子复合量较大,镀速快,耐磨性能好且纳米氧化铝分散较均匀;相比化学镀N i-P和微米A l2O3复合化学镀N i-P工艺所得镀层,纳米复合镀层具有较高的硬度和较好的耐磨性.     

复合镀用纳米金刚石悬浮液制备和复合镀铬研究

通过对市售纳米金刚石进行适当的机械化学改性、分散及分级,制得了复合镀用纳米金刚石悬浮液,悬浮液粒度分布在150nm以内,浓度可调,长期保持稳定,不含污染镀液成分;研究了标准镀铬液和添加表面活性剂镀铬液中的复合镀情况,测试了镀层的显微硬度和表面形貌,结果表明,标准镀液中加入纳米金刚石镀层,显微硬度反而降低,添加表面活性剂,镀液中的复合镀层显微硬度有较大提高,晶粒明显细化.     

非晶态Ni-P合金与纳米Al2O3微粒复合镀层的制备

利用化学镀技术,制备了非晶态Ni-P合金基纳米Al2O3复合镀层,研究了纳米Al2O3微粒的加入量、加入方式以及搅拌方式等对复合镀层组织和形貌的影响.结果表明,纳米Al2O3在加入到镀液中以前,应先选用适当的表面活性剂和分散介质制成单分散添加液,然后再加到镀槽中才可保证纳米粒子在镀层中的均匀弥散分布,在超声振动搅拌方式下,镀液中只需加入1g/L纳米Al2O3,即可得到颗粒细小、分散均匀的非晶态Ni-P合金基纳米Al2O3的复合镀层.     

表面活性剂对纳米氧化物分散稳定性的影响

采用分光光度计研究了表面活性剂对纳米Al2O3颗粒在电刷镀液中分散稳定性的影响.试验结果表明,表面活性剂聚乙二醇2000,磷酸二氢钠,乙酸铵,聚羧酸铵和柠檬酸三铵的添加对纳米Al2O3粒子在特快镍电刷镀液中的分散稳定效果不同,其中柠檬酸三铵的分散效果在单一表面活性剂中效果最佳,而表面活性剂的复合添加,分散稳定效果更好.电刷镀层显微硬度结果表明,添加表面活性剂不仅能提高纳米粒子的分散稳定性,而且能提高纳米电刷镀层的显微硬度.     

非晶态Ni-P合金与纳米A12O3微粒复合镀层的制备

利用化学镀技术，制备了非晶态Ni—P合金基纳米A12O3复合镀层，研究了纳米A12O3微粒的加入量、加入方式以及搅拌方式等对复合镀层组织和形貌的影响。结果表明，纳米A12O3在加入到镀液中以前，应先选用适当的表面活性剂和分散介质制成单分散添加液，然后再加到镀槽中才可保证纳米粒子在镀层中的均匀弥散分布，在超声振动搅拌方式下，镀液中只需加入1g／L纳米A12O3，即可得到颗粒细小、分散均匀的非晶态Ni—P合金基纳米A12O3的复合镀层。     

表面活性剂对Ni-P-Al2O3复合镀层性能的影响

目的 改善Ni-P-纳米Al2O3复合镀层的均匀性,提高其耐蚀性能.方法 采用化学镀法在Q235钢表面制备Ni-P纳米Al2O3复合镀层,分析纳米Al2O3添加量(0～10g/L)对镀层形貌的影响.施镀过程中选用不同种类的表面活性剂来分散纳米Al2O3,通过XRD分析镀层的相组成,采用SEM、EDS研究镀层形貌和成分,通过测量施镀前后纳米Al2O3的Zeta电位来研究非均一镀液的稳定性和纳米粒子的分散性能,利用电化学阻抗手段研究镀膜样品在3.5％NaCl水溶液中的耐蚀性能,从而分析镀液中表面活性剂的种类和用量对复合镀层的影响.结果 随着镀液中纳米粒子添加量的增加,镀层中Al2O3含量先增加后趋于稳定,同时镀层表面纳米Al2O3团聚现象也随之加剧.添加一定量表面活性剂之后,镀层变得均匀,纳米粒子团聚减少,其中阳离子表面活性剂(十六烷基三甲基溴化铵)在低浓度下就能对纳米Al2O3分散产生显著作用,而阴离子表面活性剂(十二烷基苯磺酸钠)需在较高浓度下才能达到相似效果.结论 当镀液中阴离子表面活性剂用量为1.25cmc,Al2O3添加量为6g/L时,镀层最为均匀,且样品在3.5％NaCl水溶液中耐蚀性能最好.     

表面活性剂对Ni-P-Al2O3-PTFE复合镀的影响

通过正交试验,研究了4种表面活性剂组合对复合粒子纳米 Al2O3、PTFE的分散状况和对(Ni-P)-Al2O3-PTFE镀层性能的影响,结果表明.阳离子表面活性剂和非离子表面活性剂适合复配作为分散剂添加到镀液中能使纳米粒子得到均匀的分散,可制备出耐磨减摩性能优良的复合镀层.     

表面活性剂和纳米PTFE对Ni-P-PTFE镀层力学和摩擦学性能的影响

在化学沉积Ni-P镀层的工艺基础上,通过改变镀液中添加的表面活性剂和纳米PTFE的含量,制备了Ni-P-PTFE复合镀层,并研究了镀液中表面活性剂和纳米PTFE的含量对复合镀层的力学和摩擦学性能的影响.研究结果表明:当镀液中的表面活性剂和纳米PTFE添加量均为6 g/L时,所得的Ni-P-PTFE复合镀层PTFE含量较高,具有优良的力学和摩擦学性能,其磨损机制主要为粘着磨损,并伴随轻微的磨粒磨损.     

纳米氧化铝的制备及应用进展

对近年来纳米氧化铝材料的各种制备方法及应用进行了综述。主要通过气相法、液相法和固相法,对纳米氧化铝的制备方法进行系统的阐述,并对其在陶瓷材料制备、材料表面改性、聚合物改性、复合材料制备以及功能材料等方面的应用进行了综述。不断开发纳米氧化铝材料的新工艺和新方法,对于纳米氧化铝的制备具有重要意义。不断开拓纳米氧化铝的应用领域,进而改善产品质量。最后,对纳米氧化铝的制备技术和应用领域的发展方向进行展望。     

镍基纳米SiC复合镀层制备与耐蚀性研究

介绍用试验方法寻找适合纳米化学复合镀层工业化生产的有效纳米粒子,采用超声波分散、添加表面活性剂、机械搅拌等综合的分散方式,保证了纳米粒子在镀液中较均匀地悬浮,对比纳米复合镀层、普通Ni-P合金镀层和微米复合镀层,证实了在不同腐蚀液中,纳米复合镀层耐蚀性能与普通Ni-P合金镀层的耐蚀性能相当,通过对比试验,在10%的NaCl溶液、10%的NaOH溶液、5%的HCl溶液中,纳米复合镀层耐蚀性能与普通Ni-P合金镀层的耐蚀性能相当。     

Properties and strengthening mechanism of brush plated nanoparticle reinforced composite coatings

Nanoparticle reinforced nickel matrix composite coatings, such as n-Al2O3/Ni, n-SiO2/Ni, n-SiC/Ni and n-TiO2/Ni, were fabricated by brush plating technique. Hardness, wear resistance and contact-fatigue resistance of the composite coatings were determined, and strengthening mechanism of the composite coatings was discussed. Results show that the composite coatings have superior properties to the Ni metal coating. Compared with properties of brush plated Ni metal coating, the composite coatings have hardness over 1.5 times and wear resistance capability of about 2.5 times. The strengthening mechanism of the composite coatings mainly includes fine-crystal grain effect, nanoparticle dispersion effect and dislocation effect.     

Effect of n-Al2O3 on electrochemical nucleation and chemical binding interaction in nickel electrodeposition

The electrochemical nucleation mechanism of nickel on the vitreous carbon electrode from n-Al2 Os/Ni composite brush plating system was investigated using potential step method. The interaction between nano-alumina and matrix metal was researched by X-ray photoelectron spectrometry. The results show that the nano-alumina leads to the increasing of the nuclei density, nucleation rate constant and crystal growth rate during nickel electrocrystallization. Nano-alumina is found to be beneficial for nucleation and growth of nickel. During the electrodeposition process, some nanoparticles are captured effectively on the growing metal surface. As the absorbed nickel atoms are diffusing on electrode surface, some of them arrive at the interface between the captured nano-alumina and the growing metal surface. The unsaturated bond of oxygen on nano-alumina surface can capture some of the absorbed nickel atoms and form nickel-oxygen chemical bond. The new nucleation and growth sites of nickel atoms appear at the interfaces between nanoparticles and metal growing surface. Nanoparticles are embedded gradually in the newly deposited nickel atoms, which leads to the formation of the composite coating. The results indicate that the nano-alumina takes part in the electrode reaction and the unsaturated chemical bond of oxygen on nanoparticle surface can combine with the absorbed nickel atoms by way of chemical bond.     

Effect of π-Al_2O_3 on electrochemical nucleation and chemical binding interaction in nickel electrodeposition

1 INTRODUCTION In recent years , nanometer composite electric brush plating technology has been developed.It is a kind of novel surface repairingtechnology ,which can prepare excellent surface coating[1 7]. The technology is at the stage of development , its foundational theory and application field must be expended. Up to now, investigations have been mainly focused on preparing coating,testing per- formance and developing new brush-plating solu- tion,little attentionis paidto the study …     

Metal Matrix Composite Coatings Manufactured by Thermal Spraying: Influence of the Powder Preparation on the Coating Properties

The purpose of this study is to manufacture metal matrix composite coatings by thermal spraying. In order to improve coating’s mechanical properties, it is necessary to increase homogeneity. To meet this objective, the chosen approach was to optimize the powder morphology by mechanical alloying. Indeed, the mechanical alloying method (ball milling) was implemented to synthesize NiCr-Cr₃C₂ and NiCrBSi-WC composite powders by using cold spraying and high-velocity oxygen fuel process, respectively. After optimizing the process parameters on powder grain size, the composite coatings were compared with standard coatings manufactured from mixed powders. SEM observations, hardness measurements, and XRD analyses were the first technologies implemented to characterize the metal matrix composite coatings. Different characteristics were then observed. When mechanical alloying process is employed to synthesize composite powders strengthened by particle dispersion, the powders tend to fracture into small segments, especially when high content of hard particles is added. Powder microstructures were then refined, which induced thinner coating morphologies and reduced porosity rate. Once an improved microstructure is obtained, manufacturing of coating using milled powders was found suitable in comparison with coatings manufactured only with mixed powders.     

Effect of surfactant on the alumina dispersion and corrosion behavior of electroless Ni?P?Al2O3 composite coatings

Electroless Ni? P? Al₂O₃ composite coatings have been synthesized on mild steel shafts using surfactant cetyltrimethyle ammonium bromide (CTAB) as dispersant. The effects of the surfactant on the alumina dispersion, weight fraction in coatings, and corrosion resistance of the composite coatings under salt spray test were investigated. Results showed that alumina dispersion was improved, whereas weight fraction was decreased, with the increasing concentration of the dispersant CTAB. The corrosion resistance of the composite coatings was found to increase with the increase in CTAB concentration up to a certain optimum of 20 mg/L, beyond which a decreasing trend of corrosion resistance was observed under salt spray test. Compared with Ni? P coating, all the Ni? P? Al₂O₃ composite coatings showed improved corrosion‐resistant properties.     

爆炸压实法制备纳米氧化铝弥散强化铜

提出了一种制备优质廉价纳米氧化铝弥散强化铜的新工艺.首先采用机械合金化法制备氧化铝和铜的混合粉末,然后经过氢气还原烧结后得到氧化铝-铜的多孔体,最后采用爆炸压实方法制得氧化铝-铜块体初坯.检测结果表明,采用该工艺制得的氧化铝-铜初坯的相对密度达到了98%以上,纳米氧化铝颗粒均匀地弥散分布在铜基体中,很好地提高了材料的硬度与强度.     

Study on Microstructures and Properties of Electro Brush-plating Composite Coatings

RECENTLY,composite materials and compositecoatings have been attracting increasing attention.It iswell known that,composite materials and compositecoatings possess unusual mechanical andphysicochemical properties.As one of the importantfunctional plating deposition in the surface treatmenttechnology,the electro brush-plating has been widelyused by engineers because of its excellent convenienceand good performances.In this paper,compositecoatings were prepared using improved electrobrush-pla…     

耐腐蚀氧化石墨烯复合涂层的研究进展

腐蚀问题会影响金属材料的安全性和耐久性,是造成工程装备和设施失效及破坏的主要原因,严重损害了经济发展和人身安全。涂层是最有效和经济的防腐措施,随着对涂层性能的要求越来越高,复合涂层材料受到科研工作者的广泛关注。石墨烯具有高导电率、高硬度和优异的阻隔性等性能,但同时具有疏水性和易团聚的特点。氧化石墨烯的结构与石墨烯相似,高长径比能够提供有效的阻隔性能,表面丰富的含氧基团为化学改性提供了反应位点,从而实现在基体中均匀分散的目的,是一种可用于增强涂层防腐能力的理想碳材料。首先介绍了氧化石墨烯的制备和化学改性方法,并且对比了不同化学改性方法的优缺点以及作用机制。然后分类阐述了氧化石墨烯复合防腐涂层的研究现状,探讨了氧化石墨烯含量、分散性和制备条件等因素对复合涂层的影响。最后从不同方面(制备工艺、分散技术、防腐机制和工程应用)分析了氧化石墨烯涂层存在的主要问题,并展望了氧化石墨烯涂层的发展方向。