复合电沉积超薄金刚石切割片磨粒分布的均匀性

针对超薄金刚石切割片磨粒分布均匀性对加工质量影响很大且又不易评价的问题,提出了一种评价复合电沉积方法制造的超薄金刚石切割片中磨粒分布均匀性的方法,并结合0.01~0.05mm超薄金刚石切割片的研制,试验研究了复合电沉积工艺参数和搅拌方式对复合电沉积超薄金刚石切割片磨粒分布的影响规律。结果表明:在溶液金刚石浓度为15g/L,阴极电流密度为1A/dm2以及搅拌停歇时间比为1∶10的条件下,复合电沉积超薄金刚石切割片磨粒分布的均匀性能够得到有效改善。     

采用丝束电极研究金属镍的快速电沉积行为

采用丝束电极(铜质和铁质)研究了金属镍的快速电沉积行为。研究表明，丝束电极表面存在腐蚀电位分布的不均匀性，经电沉积处理的丝束电极表面，也存在腐蚀电位分布的不均匀性。探讨了不同材质的丝束电极和不同镀液对金属镍的快速电沉积行为的影响。     

用射流电沉积进行局部快速电镀的工艺研究

射流电沉积是近年来发展起来的一种电沉积新工艺,具有普通电镀所不具备的一些优点.利用二维移动平台系统进行射流电沉积,研究了瓦特镍镀液的喷射速度、温度以及阴阳极间距等因素对射流电沉积的影响.研究结果表明,当镀液喷射速度为0.3 m/s,槽电压为20 V,阴阳极之间距离为17 mm时,采用该系统可在金属试样上快速获得预先设定的图形镀层,镀层分布均匀,与基体的结合力良好.     

铜纳米线阵列显微结构的表征和控制

采用多孔氧化铝(AAO)模板脉冲电沉积法制备了强辐射源用铜纳米线阵列材料,并用扫描电子显微镜(SEM)、能谱(EDS)和X射线衍射(XRD)对其进行了结构袁征.结果表明电沉积的峰值电流强度和辅助阴极可以影响铜纳米线的表面质量、长度分布均匀性和微区长度起伏.减小峰值电流强度,可以明显改善单根铜纳米线的表面质量,但是对铜纳...     

电沉积法制备ZrO_2薄膜的工艺研究

研究了水溶液中电沉积ZrO2薄膜的工艺,系统分析了镀液成分、pH值、电流密度及沉积时间对电沉积ZrO2薄膜的影响规律,并分析了薄膜的厚度、成分和形貌等。研究结果表明,在硝酸锆水溶液中加入一定量的络合剂和添加剂,可以得到与基体结合好、分布均匀的ZrO2薄膜。     

非水体系电沉积稀土填充半导体热电材料Bi2Sb3Lax及其电性能研究

在尿素-NaBr-KBr-甲酰胺体系中用工艺设备简单、成本低的电沉积方法制备Bi2Sb3Lax合金薄膜.通过EDS对电沉积薄膜的组成进行了研究,结果表明:采用控电位沉积模式,可实现铋、锑、镧三元共沉积,生成Bi2Sb3Lax合金薄膜.通过调节沉积液中各物质的配比控制Bi2Sb3Lax合金薄膜的稀土La填充量,稀土元素La的最大填充量为4.61%(原子分数).电沉积时间和电流密度对合金薄膜形态有影响,SEM观察沉积薄膜在电流密度为2000 A·m-2 ,电沉积时间为90s时表面分布均匀.沉积膜涂覆聚乙烯醇膜后进行XRD分析,图谱显示所得到的沉积物是由菱形BiSb和六方结构的单质La组成.探索了La的填充量对Bi2Sb3Lax合金薄膜电性能的影响.     

电沉积铅银合金阳极与铸造铅银合金阳极的性能

为了得到性能好、成本低的电解锌用阳极材料,在铝片表面电沉积铅、银制备了电沉积Pb-0.8％Ag合金阳极,采用坚膜浇注法制备了传统的铸造Pb-0.8％Ag合金阳极.采用恒电流极化,循环伏安曲线,交流阻抗、X射线衍射及扫描电镜对比研究了2种阳极的电化学性能、结构及形貌.结果表明:与铸造Pb-0.8％Ag合金电极相比,电沉积Pb-0.8％Ag合金阳极的阳极膜更均匀致密、更稳定,表面形成的PbO2量更多,耐蚀性和导电性更好,表面形貌更加致密和均匀.     

窄直径分布竹节状纳米碳管膜的制备和表征

采用短时间一次阳极氧化法制备了纳米级孔氧化铝(AAO)模板,有效地缩短了模板的制备时间,获得的AAO模板孔洞排列有序程度虽有所下降,但分布依然均匀.该模板有效地增加了表面积,为金属沉积提供了均匀的纳米孔洞.采用电沉积法在AAO模板上沉积了颗粒尺寸一致且分布均匀的钴催化剂层后,用CVD法在该模板上生长纳米碳管.经SEM和TEM观察,所制得的纳米碳管密度高直径分布均匀,具有单一的竹节状结构,而且直径远小于孔径.试用了生长动力学来解释这种竹节状纳米碳管的形成原因.     

CVD法制备铝化物涂层装置沉积室内前驱体流场仿真设计研究

为了制备均匀的CVD铝化物涂层,应保证沉积室内前驱气体的流场分布的均匀性.采用计算流体力学方法对沉积室内的前驱流体流场进行了仿真研究,对比了装备A、B、C型3种布风装置的CVD沉积室内流场的变化;对比了将初始进气口平均流速v经验提升至其1.5,2.0,2.5,5.0倍后沉积室内流场的变化.结果 表明:选择B型布风装置能...     

多弧离子镀在不锈钢板上沉积TiN的均匀性研究

本文对多弧离子镀在不锈钢板上沉积TiN涂层的均匀性进行了研究,分析了影响涂层均匀性的主要因素.结果表明,弧基距、磁场强度、气体压力及基片温度对涂层的均匀性起着决定性的作用.     

电沉积铜的电阻率和硬度的时间效应

为了研究钢基体上电沉积铜的电阻率和硬度随阴极电流密度及时间的变化规律,通过制备不同电流密度的电沉积铜样品,分别采用直流电桥式电阻仪和显微硬度计测定样品的电阻率和硬度.结果表明,电沉积铜的硬度和电阻率随阴极电流密度增大而提高,然而经时效时理后会下降.阴极电流密度增加,电沉积铜层的晶粒变小,而时效处理能够提高晶粒度和降低缺陷密度.     

Ultrasonic Electrodeposition of Cu–SiC Electrodes for EDM

Cu-SiC composite electrodes composed of both a Cu matrix and dispersed inert SiC particles were fabricated for electrical discharge machining (EDM) using the ultrasonic-aided electrodeposition technique. The influence of ultrasonic power on the surface morphology, content of SiC particles, and EDM wear rate of the fabricated Cu-SiC composite electrode were investigated. Results show that the incorporation of SiC particles into the composite electrode was enhanced and that the uniformity of particle distribution in the Cu matrix improved when the ultrasonic dispersion was initiated during electrodeposition. The composite that was generated at low ultrasonic power contained more SiC than that produced at high ultrasonic power. Moreover, the Cu-SiC electrode fabricated at low ultrasonic power displayed the least erosion wear during EDM.     

Nanoscopic study of chemical species during uranium electrodeposition for alpha spectrometry sources

High resolution alpha spectrometry (AS) is commonly applied for the determination of actinides and other alpha-emitting nuclides in many applications. Electrodeposition is the standard procedure for preparing α-particle sources usually made of a thin and uniform radioactive deposit onto a metallic substrate. Natural U sources prepared by the Hallstadius method are known to contain co-deposited Pt from the anode. In this sense, the main aim of this work is to conclusively review the behaviour of Pt and U in the electrodeposition process and their distribution in the resulting deposit, factors that are responsible for the thickness and uniformity of the sources. In addition to new scanning electron microscopy/energy dispersive spectroscopy (SEM–EDX) and X-ray absorption fine structure (XAFS) data, the electrodeposited surface has been analyzed using both atomic force microscopy (AFM) and synchrotron radiation Grazing Incidence X-ray diffraction (GI-XRD). The results concerning morphology of the deposit, surface roughness, topography and surface structure obtained from sources prepared at different electrodeposition times agree with the AS results concerning electrodeposition yield and spectral resolution.     

A facile approach to fabricate Ni inverse opals at controlled thickness

A vertical electrophoretic deposition method was employed to fabricate polystyrene (PS) colloidal crystals with negligible defects and considerable surface uniformity. Subsequently, the interstitial voids within the colloidal crystals were electroplated with Ni, followed by selective removal of the PS microspheres. With careful adjustment in the processing parameters, we were able to obtain Ni inverse opals at predetermined thickness in relatively short time. The inverse opals revealed superb structural stability and surface uniformity. Because the electrophoresis and electrodeposition were both carried out in a solution state, this fabrication scheme enables facile construction of inverse opals on conductive substrates over conventional approaches.     

Pulse Electrocodeposited Ni–WC Composite Coating

In the present work, tungsten carbide (WC) particulate of average size 10 µm were electrocodeposited in the nickel metal matrix, to form metal matrix composite (MMC) coating over the EN8 steel substrate. The electrodeposition of Ni–WC particulate composite coating was carried out using the Watt's bath under the influence of varying current density and duty cycle. It was found that current density of 0.02 A/cm² was sufficient to start the codeposition kinetics. But, good quality of electrodeposition was obtained at a current density of 0.04 A/cm². The WC particulate entrapment and distribution of WC particles in Ni matrix according the variation in experimental parameters has been reported. The dense and compact microstructure was obtained at a current density of 0.04 A/cm² and duty cycle of 30%. Microhardness and corrosion resistance properties of composite coating were also evaluated and reported.     

阳极喷嘴口径对射流电沉积的影响

利用自行设计的实验装置,研究了瓦特镍射流电沉积不同阳极喷嘴口径下电压与电流、电流密度、电流效率关系,以及阳极喷嘴口径对沉积层的金属分布的影响.研究发现:可用电流密度高达800A/dm2,沉积物呈圆柱形分布,沉积物直径几乎与相应的0.8,1.2,1.6mm阳极喷嘴口径一致.当喷嘴口径为1.6mm时电流效率为89.8%,而喷嘴口径为0.8mm时只有64.3%.     

电沉积法制备块体纳米晶材料的研究进展

综述了电沉积法制备块体纳米晶材料的原理;阐述了电流密度、电流波形、有机添加剂等工艺参数对沉积层晶粒尺寸的影响;介绍了直流电沉积、脉冲电沉积、喷射电沉积和复合电沉积等几种常见的电沉积方法;概述了电沉积法制备块体纳米晶材料的国内外研究现状;探讨了电沉积块体纳米晶材料的力学性能、磁学性能、耐蚀性能、热稳定性及其应用前景.     

Current distribution measurement in YBCO thin film for a superconducting fault current limiter

Current distribution in the superconducting film for a resistive fault current limiter is important, because it influences AC loss and a uniformity of S/N transition. The lateral current distribution of the film was reconstructed from the magnetic field distribution which is measured by multiple Hall probes. The following results were obtained. (1) Non-uniform current distribution in the superconducting film was observed when the current was less than 1.3 times of critical current (I_c). (2) The current in a superconducting film was uniform when the current was much higher than I_c. The current can be considered uniform when the film works as a fault current limiter, because the S/N transition starts about twice of I_c. (3) The validity of the measurement was verified by the comparison with the electric circuit simulation.     

Fabrication of free-standing Cu nanorod arrays on Cu disc by template-assisted electrodeposition

Free-standing Cu nanorod arrays on Cu foil have been fabricated by a template-assisted method. Cu nanorods were potentiostatically deposited on mechanically polished Cu foil using anodized aluminum oxide templates as the deposition mask. Three electrolyte systems were compared, including two acid copper sulfate based solutions and one alkaline solution. The most uniform nanorods were achieved in the alkaline electrolyte. The weight gain per unit area after electrodeposition has been used as a direct measure of average length of deposited Cu nanorods. It was found that our control over the uniformity in nanorod length across the array is important in reaching the maximized aspect ratio without aggregation. Through controlling the weight change it was possible to control the aspect ratio of nanorods and to avoid aggregation of nanorods. Our capability to fabricate free-standing Cu nanorod arrays of uniform height with maximized aspect ratio on Cu foil is especially important in applying this nanostructured Cu as a current collector in Li ion batteries.     

Nickel electrodeposition on copper substrate for cyclotron production of <Superscript>64</Superscript>Cu

Natural nickel electrodeposition on a copper substrate with a gold layer was studied with the aim of production of ⁶⁴Cu radionuclide. The electrodeposition experiments were carried out in acid plating baths. The operating parameters such as pH, temperature, and current density were optimized. The current efficiency was measured at different current densities. The optimum conditions of the nickel electrodeposition are as follows: 5.7 g 1⁻¹ nickel, pH 3–4, dc current density 85.54 mA cm⁻², and 55°C, with 97% current efficiency. SEM photomicrographs demonstrated fine-grained structure of the deposit obtained from the optimum bath. A 46-μm high-quality layer was deposited on a gold layer of the copper substrate.