摩擦喷射电沉积制备Ni-Al2O3纳米复合镀层

采用摩擦喷射电沉积工艺制备了N i-A l2O3纳米复合镀层。研究了电压、镀液中纳米颗粒含量、镀液喷射速度、镀笔相对运动速度等工艺参数对镀层沉积速度以及镀层中纳米颗粒含量的影响。结果表明,电压对镀层沉积速度影响较大,电压、镀液中纳米颗粒含量对复合含量的影响较大。扫描电镜及能谱测试显示,该纳米复合镀层表面较为平整、致密,纳米颗粒在镀层中呈均匀弥散分布,含量在2%~5%。     

摩擦喷射纳米复合电沉积技术研究

摩擦喷射纳米复合电沉积技术是一项获得功能性复合镀层的表面工程新技术。文中阐述了该技术的原理、特点、用途、装置，溶液、工艺，镀层的组织和性能，镀层强化机理，并在最后对该技术的发展进行了展望。     

SiC纳米颗粒增强型复合镀层的研究进展

SiC纳米颗粒作为增强相添加到复合镀层中,可提高镀层的综合性能。分析了SiC纳米颗粒对镀层的表面形貌、显微硬度、耐磨性和耐腐蚀性等性能的影响机理,讨论了SiC纳米颗粒浓度、电流密度和搅拌速度等工艺参数对制备复合镀层的影响,阐述了不同电沉积方式对制备复合镀层的影响,指出在SiC纳米颗粒增强型复合镀层研究中尚需解决的若干问题。     

硫酸盐镀液中紫铜电沉积Ni-Co/WC复合镀层的工艺条件优化

在硫酸盐镀液中加入纳米WC颗粒,通过电沉积在紫铜表面制备了Ni-Co/WC复合镀层.采用单因素分析法考察了镀液中纳米颗粒浓度、温度、阴极电流密度和搅拌速度对复合镀层硬度的影响,确定了电沉积Ni-Co/WC复合镀层的最佳工艺条件为:镀液中纳米颗粒浓度11 g/L、温度60℃、阴极电流密度5 A/dm2、搅拌速度450 r...     

电沉积纳米复合镀层的研究现状

纳米复合电沉积是一种新兴的复合表面技术。阐述了纳米颗粒与金属共沉积的机理、工艺条件对纳米复合电沉积的影响。以及纳米复合共沉积的应用。纳米与金属共沉积可明显提高镀层的硬度、耐磨、耐蚀、光催化和电接触性能。指出了纳米复合电沉积现存的问题，并为今后的研究提出了建议。     

电沉积铜基自润滑复合材料的研究进展

从4个方面综述了复合电沉积工艺制备铜基自润滑材料的研究进展,包括固体润滑剂、复合电沉积工艺、摩擦性能和复合电沉积机理。常用的固体润滑剂主要有石墨、MoS2、WS2,、PFFE等。影响复合材料性能的主要因素有电流密度、微粒浓度、搅拌程度等。关于微粒和金属共沉积的内在规律存在不同的理论模型,主要有Guhlielmi模型、MTM模型、Valdes模型、运动轨迹模型和并联吸附模型。简单介绍了纳米复合镀层和复合电铸的发展概况与趋势。提出阴极和颗粒接触局部区域的细节将成为复合电沉积机理的研究重点。     

Ni基金属微纳米颗粒复合涂层的研究进展

从镀层的电沉积工艺、镀层组织结构及性能特点等方面出发,综述了电沉积工艺参数对镀层组织结构和耐蚀性、耐磨性、电解析氢性能的影响,以及后续的热处理工艺对镀层组织及性能的影响。以Ni基金属复合颗粒镀层的电沉积机理和合金镀层的应用前景为出发点,提出了电沉积Ni基金属复合颗粒镀层的未来研究方向。     

活塞表面Ni-P-SiC复合镀层的电沉积及性能表征

从替代电镀铬的绿色表面处理技术出发,通过复合电沉积技术在活塞表面制备Ni-P-SiC复合镀层.电沉积前,对纳米SiC颗粒进行酸洗改性.利用扫描电子显微镜(SEM)、能谱分析(EDS)和显微硬度计研究了阴极电流密度对复合镀层性能的影响,采用往复式摩擦磨损试验测试其耐磨性,并用三维轮廓仪对其磨损率进行表征.结果表明:碳化硅...     

复合电沉积研究的新动向

复合电沉积是获得功能性复合材料镀层的一种新工艺。综述了近年来国内外在复合电沉积研究方面的新动向。重点探讨了多元复合电沉积、纳米复合电沉积、功能梯度材料复合电沉积的研究现状和发展趋势。这三类复合镀层在耐磨性、抗腐蚀性和抗高温氧化性等方面比传统的复合镀层更优越。展望了今后复合电沉积的研究和应用前景。     

碳钢表面铜-碳化硅纳米复合镀层的制备及其性能研究

在Q235碳钢表面先预浸镀铜,然后采用超声-电沉积方法获得Cu-SiC纳米复合镀层。研究了纳米SiC含量对纳米复合镀层表面形貌的影响,讨论了阴极电流密度、超声功率、温度和电沉积时间对复合镀层显微硬度的影响,获得了较佳的工艺条件:镀液中SiC纳米颗粒含量9g/L,阴极电流密度6A/dm2,超声波功率200W,镀液温度30°C,电沉积时间40min。在此条件下制备Cu-SiC纳米复合镀层,测试了镀层的结合力,并与普通铜镀层进行比较,研究了复合镀层的表面形貌、显微硬度以及在3.5%NaCl溶液中的电化学阻抗谱(EIS)。结果表明,所制备的复合镀层结合力良好,其表面颗粒尺寸在0.5～1.0μm之间(小于普通铜镀层的1～4μm),显微硬度和反应电阻分别为294.6HV和2446.5.cm2(大于普通铜镀层的162.0HV和1538.7.cm2)。Cu-SiC纳米复合镀层具有较好的机械性能和耐腐蚀性能。     

纳米粒子复合镀的研究现状

阐述了纳米粒子在复合镀层制备过程中的沉积机理,并对纳米粒子复合镀层的结构、性能及其影响因素进行了分析.综述了近几年来国内外纳米粒子复合镀层的研究现状和发展趋势.分析了纳米粒子复合镀层比一般的复合镀层具有更高的硬度、更好的耐磨性、耐蚀性、高温抗氧化性和光、电催化性能的原因.最后,对纳米粒子复合镀技术的发展及其应用前景进行了展望.     

化学镀(Ni-P)-WC纳米微粒复合镀层的研究

采用化学镀的方法制备(Ni-P)-WC纳米微粒复合镀层,研究了镀液中WC纳米微粒的添加量对镀层中微粒含量的影响,通过扫描电镜观察了(Ni-P)-WC纳米微粒复合镀层的表面形貌。研究发现,纳米微粒镀层的硬度随着镀层中WC纳米微粒含量的增加而提高。通过测量(Ni-P)-WC纳米微粒复合镀层在NaCl溶液中的开路电位曲线和电化学阻抗谱,发现其耐蚀性能要优于合金镀层。     

Surface modification of TiO2 nano-particles with silane coupling agent and investigation of its effect on the properties of polyurethane composite coating

Surface modification and characterization of TiO₂ nano-particles as an additive in a polyurethane clear coat were investigated. For the improvement of nano-particles dispersion and increasing possible interactions between nano-particles and polymeric matrix, the surface of the nano-particles was modified with amino propyl trimethoxy silane (APS). Equivalent amount of APS for monolayer formation on the nano-particles surface was determined by means of elemental analysis (CHN). The grafting of APS on the TiO₂ nano-particles surface was characterized with TGA and FTIR techniques. Mechanical properties of coatings containing various amount of TiO₂ nano-particles were evaluated with DMA technique and tensile strength measurement. UV–vis spectroscopy was employed to evaluate the absorbance and transmittance of the nano-TiO₂ composite coatings in the wavelength range of 230–700 nm.     

Zn–Ni/nano-TiO2 composite electrodeposits: surface modifications and protective properties

Zn–Ni composite coatings were obtained by electrochemical co-deposition of TiO₂ nano-particles (mean diameter 21 nm). Zn–Ni alloy coating was also produced under the same experimental conditions for comparison. The surface morphology, crystallographic structure, and the grain size of the deposits were investigated, along with the percentage of the embedded nano-particles in Zn–Ni matrix, as a function of concentration of TiO₂ nano-particles in the bath. As the titania incorporation percentage is increased, a grain refinement in the nanometer region was revealed followed enhanced microhardness values and an improvement of the content of the nickel in the alloy. Annealing of all coatings at 200 °C revealed the crystallization of the matrix accompanied by a decrease of microhardness followed by stability for 24 h. The corrosion behavior of Zn–Ni/nano-TiO₂ composite coatings with various amount of particle content was mainly studied by electrochemical impedance spectroscopy in 3 % NaCl. It was seen that Zn–Ni/nano-TiO₂ composite coatings exhibited higher corrosion resistances comparing to Zn–Ni alloy coating and corrosion protection improved with increasing nano-TiO₂ in coatings.     

Mechanical and anticorrosive properties of copper matrix micro- and nano-composite coatings

In the frame of the research domain of the production of metal matrix composite coatings, the aim of the present work was the production of copper electrodeposits containing micro- and nano-particles of SiC. The electrodeposition was carried out under dc conditions using a copper pyrophosphate plating bath into which micro- or nano-SiC particles were suspended. The composite coatings were tested and compared to pure copper coatings regarding their microstructure, mechanical and anticorrosive properties.The codeposition of SiC in the metal matrix changed the microstructure of the copper leading to improvement of both their mechanical and, in some cases, their protective properties. The Vickers microhardness presented an increase of about 35% and 61% in the case of SiC micro- and nano-particles incorporation while the increase of the abrasion resistance was 88% and 58%, respectively.The incorporation of the micro-particles lead to gaps formation among the SiC micro-particles and the metal matrix, thus lowering the resistance on both uniform and localized corrosion in comparison to the pure copper-coated specimens while the codeposition of SiC nano-particles produced deposits with higher resistance to both uniform and localized corrosion.     

SiC强化镍基纳米复合电刷镀层的干摩擦磨损特性

采用电刷镀技术制备了快速镍和,n-SiC/Ni、n-SiC/Ni-W复合镀层,研究了镀层的干摩擦磨损特性,测定了镀层的显微硬度,采用扫描电子显微镜(SEM)观察分析了镀层磨痕形貌.结果表明:纳米粒子的加入可以显著地提高镀层的耐磨性.纳米复合镀层的磨损机制以磨粒磨损为主,而纯镍镀层以粘着磨损和磨粒磨损为主.     

Polyhedral oligomeric silsesquioxanes as titanium dioxide surface modifiers for transparent acrylic UV blocking hybrid coating

Architectural coatings are often recommended to enhance the durability of wood in exterior environment however the coatings itself are not UV stable enough for long term protection. For this reason inorganic UV absorbers like nano TiO₂ in rutile crystal form are of great research interest in last decade. It's advantage is UV reversible absorption activity in polymer composite like coating during weathering [1]. On the other side the TiO₂ surface has limited compatibility with polymers what can result in non-stable dispersion. To achieve a better compatibility between nano-particles and polymer matrix in coating, the use of different inorganic/organic surface modification of TiO₂ rutile nano-particles is recommended.     

Sol-enhanced electroplating of nanostructured Ni-TiO2 composite coatings—The effects of sol concentration on the mechanical and corrosion properties

Novel sol-enhanced Ni-TiO₂ nano-composite coatings were electroplated by adding a transparent TiO₂ sol into the traditional electroplating Ni solution. It was found that the structure, mechanical properties and corrosion resistance of the nano-composite coatings were largely determined by the sol concentration. The higher sol concentration in the plating electrolyte led to a higher content of TiO₂ nano-particles in the coating matrix. The coating prepared at the sol concentration of 12.5 mL/L had the best microhardness, wear resistance and corrosion resistance. Adding excessive sol to the electrolyte changed the surface microstructure, caused cracking on the coating surface and deteriorated the properties. It was demonstrated that the corrosion resistance of the composite coatings is determined by two factors: surface microstructure and incorporation of TiO₂ nano-particles.     

Kinetics study of living microemulsion polymerization mediated by reversible addition-fragmentation chain transfer

The present work focuses on the development of functional polyurethane hybrids through the incorporation of surface modified TiO₂ nanoparticles. For improving the nano-particle dispersion and increasing possible interactions between nano-particles and polyurethane matrix, the surface of the nano-particles was modified with 1,3,5-triazine core silane coupling agent. The surface modification of nanoparticles was confirmed by FESEM, FT-IR and Raman spectroscopic techniques. The functionalized nanoparticles were then inscribed in 0, 1 and 2 weight percentages into polyurethane matrix. The as prepared composite coatings were investigated for various anti-microbial, thermo-mechanical and anticorrosive properties. The tensile strength of polyurethane was improved by 300 % upon addition of 2 wt% of modified TiO₂ nanoparticles as compared to neat polyurethane. Fog test and electrochemical polarization studies suggest that the corrosion resistance increases with increase of the modified TiO₂ content in the coating formulation. The composite coatings also have good resistance towards various bacterial and fungal stains as compared to the pure polyurethanes. The coatings substantially gain hydrophilic nature symbiotically with TiO₂ content suggesting its potential application as self-cleanable material.     

水性隔热涂料的制备与研究

采用化学沉积法使TiO2以纳米粒子的形式包覆于空心玻璃微珠表面,成功制备了TiO2纳米晶/空心玻璃微珠复合填料,并以改性微珠及空心玻璃微珠作为填料制备隔热涂料,对其光反射性能、隔热效果、隔热效果的影响因素进行了研究。结果表明,TiO2在空心玻璃微珠表面包覆效果良好,且经过热处理后空心玻璃微珠破损率很低。以改性微珠作为填料制备的涂料,涂膜对太阳光主要能量波段的光反射性能得到显著提高,其隔热效果较普通外墙涂料和空心玻璃微珠涂料相比有了明显的提高,且改性微珠添加量的多少对隔热温差的影响要大于厚度和白度对隔热温差的影响。