镍钨合金电沉积的电流效率和镀层显微硬度

通过调节镀液中不同的Ｎｉ／Ｗ比例、温度和沉积电流密度,研究在焦磷酸盐体系中镍钨合金电沉积的电流效率、沉积层和组成和显微硬度。实验结果表明：合金共沉积的电流效率不高。为了尽量提高合金的沉积电流效率,主要途径宜增大镀液中硫酸镍和钨酸钠的浓度;提高合金沉积电流密度,降低镀液中［Ｎｉ］／［Ｗ］比例,则镀层中的钨含量增大;合金沉积层的显微硬度随镀层中的Ｗ含量提高而增大。     

电沉积Fe-36%Ni磁性合金工艺的研究

采用电沉积法制备Fe-36％Ni磁性合金。通过正交实验研究了nFe2 ／nNi2 、电流密度、镀液pH值、镀液温度与合金中铁含量的关系,用极差法分析了各工艺参数对Fe—Ni合金镀层成分的影响,并确定了最佳工艺条件为nFe2 ／nNi2 0.6,镀液pH值3．5,施镀温度65℃,阴极电流密度6A／dm2。实验结果表明,合金镀液中nnFe2 ／nNi2 较大,电流密度增加,pH值升高,均有利于镀层Fe含量的提高：实验所得合金镀层光亮、致密、外观平整,显微结构是层状,镀层中wFe为64．1％,wNi为35．9％,符合Fe-36％Ni合金成分设计要求。     

工艺参数对电镀镍铜合金镀层成分及相结构的影响

采用由200 g/L NiSO4·6H2O、10 g/L CuSO4·5H2O、80 g/L Na3C6H5O7·2H2O、0.2 g/L C12H25SO4Na和0.5 g/L糖精钠组成的镀液,在10~60 mA/cm2、pH=2.5~5.0和25~50°C条件下电沉积制备了NiCu合金镀层。探讨了镀液pH、电流密度、温度等工艺参数对镍铜合金镀层相结构和组成的影响。结果表明,NiCu合金镀层的铜含量随电流密度或温度升高而增大。但随pH增大,镀层铜含量降低,pH小于4.0时,NiCu合金镀层中含有单质铜。     

用于电子行业的高铁Fe-Ni合金制备工艺参数优化

在铜板表面电沉积Fe-Ni合金。采用单一变量法研究了镀液配方、电流密度、镀液温度、镀液pH值和搅拌速率对Fe-Ni合金中Fe的质量分数的影响。结果表明:Fe的质量分数随电流密度的增加和镀液温度的升高而降低,随镀液pH值的升高和搅拌速率的增大而升高;向镀液中加入适量的稳定剂和配位剂,对提高Fe-Ni合金中Fe的质量分数有利。采用配方B,在电流密度1.0A/dm~2、镀液温度40℃、镀液pH值3.0、搅拌速率150r/min的条件下,电沉积得到的Fe-Ni合金的形貌良好,Fe的质量分数为52.83%。     

电沉积制备铁-镍因瓦合金的工艺研究

采用硫酸盐镀液体系,在紫铜箔上电沉积制备了Fe-Ni合金镀层,研究了镀液成分(如镀液中添加剂含量.Ni2+/Fe2+浓度比)及主要的沉积工艺参数(包括阴极电流密度、温度和搅拌速率)对镀层表面质量、成分及组织的影响.镀液成分及最佳工艺参数为:0.3 mol/L NiSO4·6H2O,0.08 mol/L FeSO4·7H2O,2g/L糖精,0.35 g/L 1,4-丁炔二醇,电流密度3.7 A/dm2,施镀温度40℃,搅拌速率200 r/min.     

电沉积Sn—Bi合金工艺的研究

采用硫酸盐镀液在铜基体上电沉积Sn-Bi镀层,利用能谱仪(EDS)、扫描电子显微镜(SEM)和X射线衍射仪(XRD)研究了电沉积参数对镀层成分和微观结构的影响.结果表明:镀层中Sn的质量分数随着镀液中Sn的质量浓度的增大而增大,同时随着电流密度的增大,Sn的质量分数不断减少;Sn-Bi镀层主要由四方晶系的Sn和菱形晶系的Bi组成;另外,研究发现电流密度对镀层形貌影响较大.     

镍基微胶囊彩色复合镀层制备工艺研究

采用溶剂蒸发技术制备平均粒径为10μm的染色微胶囊;研究了用瓦特镀镍液电沉积彩色微胶囊复合镀层的工艺,讨论了镀液中微胶囊颗粒的含量、操作温度、pH值、阴极电流密度,对镀层中微胶囊复合含量的影响。结果表明,选择合适的工艺参数可以获得结合力强、微胶囊覆盖率超过30％的镍基彩色微胶囊复合镀层。     

电沉积非晶合金的形成条件

通过对Fe-W、Ni-W等9种非晶合金电沉积过程的分析,总结了电沉积条件(镀液组成、电流密度、镀液温度、pH)及镀层组成对镀层结构的影响,认为电沉积条件直接影响镀层中添加元素的含量,间接影响镀层结构。添加元素及其含量才是形成非晶镀层的决定性因素。     

镍-纳米二氧化钛复合镀层的制备及性能

以多孔泡沫镍为基体,通过在瓦特镀镍液中复合电沉积,得到Ni-TiO2复合镀层.研究了阴极电流密度、pH、时间、镀液中纳米TiO2质量浓度及分散剂种类对Ni-TiO2复合镀层的TiO2含量、表面形貌及光催化性能的影响.通过正交试验得到最佳工艺条件为:TiO2质量浓度10g/L,pH=4.0,阴极电流密度30 mA/cm2...     

次磷酸钠对锌–镍合金电沉积和镀层耐蚀性的影响

在乙酸盐-铵盐体系电镀锌–镍合金镀液配方中添加次磷酸钠,以45钢为基体电沉积锌–镍–磷合金。通过循环伏安法和小槽电镀实验研究了pH、温度和电流密度对镀层成分的影响,采用扫描电镜、能谱、X射线荧光、X射线衍射等技术对镀层形貌和微观组织进行表征,采用Tafel极化曲线和电化学阻抗谱对镀层的耐蚀性进行测试。结果表明:在不含主盐的基础镀液中,次磷酸钠的P不能被还原出来,而次磷酸钠与Zn²⁺、Ni²⁺共存时有助于Ni的沉积,对Zn的沉积无明显影响;温度升高则镀层中Zn减少,Ni和P增多;降低pH有利于锌–镍共沉积;镀层的P含量随电流密度增大而减少。P元素的掺入能完全消除锌-镍合金的裂纹,细化镀层晶粒。低P含量(P质量分数低于1%)的锌–镍–磷合金镀层具有比高P含量(P质量分数大于10%)的镀层更好的耐蚀性。     

Electrodeposition of Ni-W-B amorphous alloys

Partial polarization curves at the glassy carbon rotating disc electrode have been used to study the electrodeposition of Ni and Ni-W alloy from citrate-containing solution. For deposition of Ni-W alloys, the partial polarization curves indicate diffusion control for nickel reduction and stoichiometric limitation for tungsten deposition by the composition of the alloy. Plating experiments show that current efficiency of the electrodeposition and composition of the resulting alloy depend on the parameters of the electrolysis. The best conditions for electrodeposition of the alloy Ni-W-B are current density of 45–50 mA cm^–2, temperature of 60–70 °C, Ni(II) concentration of 20–25 mm, and pH 8.5. Pulsed galvanostatic plating at 1 Hz increased slightly the current efficiency. The concentration of Ni(II) in the solution can be self-regulated by using a nickel bipolar electrode in the cathode compartment.     

Electrodeposition of Ni, Co and Ni-Co alloy powders

In this paper the polarization characteristics of the processes of Ni and Co powders and Ni-Co alloy powders electrodeposition from ammonium sulfate containing supporting electrolyte are investigated as a function of Ni²⁺ and Co²⁺ ions concentrations. It is shown that the correct polarization curves for Ni and Co powders and Ni-Co alloy powders electrodeposition could be obtained only after IR drop correction, since the total current density of electrodeposition at the most negative potential of −1.4 V versus Ag|AgCl is extremely high (up to about 3-6 A cm⁻²) as a consequence of simultaneous hydrogen evolution which starts immediately after the beginning of metals (alloys) deposition. After determining the current density for hydrogen evolution and its subtraction from the total current density, correct polarization curves for Ni and Co powders and Ni-Co alloy powders electrodeposition are obtained. They are found to be different for each ratio of Ni²⁺/Co²⁺ ions concentration. It is also concluded that the shape of the polarization curves in all cases is practically defined by the shape of the polarization curve for hydrogen evolution. The morphology and composition of electrodeposited powders were also found to be sensitive to the ratio of Ni²⁺/Co²⁺ ions concentration.     

Effect of some operating variables on the characteristics of electrodeposited Cu?Ni alloys with and without α-Al2O3 and TiO2 inert particles

A study was carried out on the electrodeposition of Cu Ni alloys containing inert (α-Al₂O₃ and TiO₂) particles from a selected citrate bath. The cathodic polarization curves show that alloy deposition occurs at more noble potentials relative to either of the two parent metals and this indicated the formation of a solid solution. The addition of the inert particles into the selected bath led to a polarization-increasing effect and this increased with increases in the size and concentration of the particles in the bath. An explanation of the mechanism of codeposition of the inert particles with the alloy has been presented. On controlling the bath composition, Cu Ni alloys containing 11–40% of nickel could be deposited. The effect of the operating variables such as the concentration of the metal ions in the bath, pH and current density on the alloy composition indicated that the formation of the Cu Ni alloy belongs to the regular alloy deposition system. The current efficiency of the alloy deposition is relatively lower than for either of the two parent metals, from similar baths, and ranges between 76 and 84%. The microhardness of the deposited Cu Ni alloy improved from 170 to 248 kfg mm⁻² as a result of codeposition of 1–2% of the inert particles. A direct correlation between the surface morphology of the deposited Cu Ni alloy, as revealed by SEM, and its microhardness could be detected. X-ray diffraction studies confirmed the dispersion of the α-Al₂O₃ and TiO₂ phases in the Cu Ni alloy phase.     

高活性镍钴铁三元合金电极的制备及析氢性能研究

为进一步提高镍基电极的析氢性能,采用恒电位沉积法,通过改变镀液中各合金的质量浓度比、沉积电位、沉积时间等条件,制备出一种高活性的镍钴铁三元合金电极。通过测定电极在1 mol/L的NaOH溶液中的极化曲线,得到最佳的沉积工艺条件为:36.25 g/L NiSO_4·6H_2O,1.25 g/L NiCl_2·6H_2O,5 g/L CoSO_4·7H_2O,7.5 g/L FeSO_4·7H_2O,10 g/L H_3BO_3,0.5 g/L抗坏血酸,1 g/L十二烷基硫酸钠,pH=4.0,电沉积电位-1.45 V,电沉积时间300 s。阴极极化曲线测试结果表明在5 A/dm^2的条件下,镍钴铁三元合金电极的析氢过电位降低至121 mV,相比于纯镍电极过电位降低近50%,相比于镍钴电极过电位降低近35%。     

钯及其合金的电沉积

介绍了钯及其合金的应用、电沉积和与金沉积层的性能比较。概述了本科研组在Pd、Pd-Ni、Pd-Co和Pd-Fe合金电沉积的主要研究结果，包括镀液组成、沉积条件、电沉积、电结晶和镀层性能。     

pH值对Ni-Cr-Mo合金电沉积机制的影响

采用循环伏安曲线、电化学阻抗谱、扫描电镜、能谱仪等手段,研究了pH值对Ni-Cr-Mo合金电沉积机制的影响。结果表明:当pH值为3.0时,循环伏安曲线的共沉积还原峰最正,电化学阻抗谱的极化电阻最小,Ni-Cr-Mo合金的电沉积最容易发生。当pH值不大于3.0时,Ni-Cr-Mo合金的电沉积受动力学和扩散混合控制;当pH值大于3.0时,Ni-Cr-Mo合金的电沉积受动力学过程控制。随着pH值的增大,Ni-Cr-Mo合金的晶粒尺寸逐渐增大,Cr的质量分数先增大后减小,Ni、Mo的质量分数均先减小后增大。     

Morphology and composition of the Fe-Ni powders electrodeposited from citrate containing electrolytes

The electrodeposition of the Fe-Ni powders from citrate containing electrolytes for different Ni/Fe ions concentration ratios, using Fe(III) and Fe(II) salts at pH 4.5 and pH 4.0 respectively was investigated by the polarization measurements and cyclic voltammetry. The morphology and composition of the electrodeposited powders were investigated by SEM and EDS analysis. The EDS analysis of the alloy powders confirmed anomalous co-deposition of Fe and Ni from both solutions, with the one obtained using Fe(III) salt being more pronounced. The morphology of electrodeposited powders was found to depend on the Ni/Fe ions concentration ratio, as well as on the valence of Fe ions used. A common characteristic for all powder samples was the presence of cone shaped cavities and nodules, while for the ratio Ni/Fe = 9/1 in both electrolytes pagoda like crystals, corresponding to the FeNi₃ single crystal, have been detected. In the case of Fe(III) containing electrolytes current efficiency for powder electrodeposition was very small (about 1-2%) due to the first step in the electrochemical reaction being reduction of Fe(III) into Fe(II), while in the case of Fe(II) containing electrolytes current efficiency for powder electrodeposition varied between about 15% and 8% depending on the Ni/Fe ratio.     

电沉积制备Zn-Ni合金及其耐蚀性的研究

研究了镀液组分对Zn-Ni合金的电沉积过程、成分、耐蚀性和表面形貌的影响。研究表明:电沉积Zn-Ni合金属于一种典型的异常共沉积现象。镀液中的Zn2+会阻碍Ni 2+的放电过程,使得合金中Ni的质量分数降低。通过增加镀液中Ni 2+的浓度,可以有效增大Zn-Ni合金中Ni的质量分数。含Ni 17%的Zn-Ni合金具有最佳的耐蚀性。合金中Ni的质量分数的增大,有利于细化颗粒,降低表面粗糙度。     

Anomalous codeposition of Co–Ni: alloys from gluconate baths

Thin films of cobalt–nickel alloys were galvanostatically deposited onto steel substrates from gluconate baths. Cathodic polarization curves were determined for the parent metals and Co–Ni alloy. The effects of bath composition, current density and temperature on cathodic current efficiency (CCE) and alloy composition were studied. The deposition of Co–Ni alloy is of anomalous type, in which the less noble metal (Co) is preferentially deposited. The CCE of codeposition is high and increases with increase in temperature and current density, but it decreases as the [Co²⁺]/[Ni²⁺] ratio in the bath increases. The percentage of Co in the deposit increases with increasing cathodic current density, temperature and increasing Co²⁺ ion concentration. The structure and surface morphology of the deposit were studied by XRD, ALSV and SEM. The results showed that the alloys consisted of a single solid solution phase with a hexagonal close packed structure.