化学镀镍-铜-磷三元合金工艺的研究

为提高化学镀镍－磷合金镀层的性能及获得多种性能的合金镀层以拓宽其应用范围。在化学镀镍－磷合金液中加入硫酸铜制得镍－铜－磷三元合金。研究了镀液中硫酸镍、次磷酸钠、柠檬酸钠、硫酸铜、稳定剂、光亮剂的含量以及pH值和温度等因素对合金镀层的外观、沉积速度及铜含量的影响。通过5％氯化钠溶液和10％硫酸溶液浸泡试验比较了所得镍－铜－磷合金镀层与镍－磷合金镀层以及前人制得的镍－磷合金镀层的耐蚀性，同时比较了上述镀层的其它性能。结果表明，所得镍－铜－磷合金镀层的耐蚀性、外观、结合力、孔隙率、沉积速度、硬度和耐磨性等性能优于镍－磷合金及前人制得的镍－铜－磷合金镀层。     

化学复合镀镍-磷-氧化铝工艺研究

为进一步提高化学镀镍磷合金层的性能，在镀液中加入氧化铝粒子制度得镍－磷－氧化铝复合镀层。研究了镀液中各成分及操作条件对镀速的影响，并对镀层的组织结构和性能进行了测试。结果表明，该工艺镀液稳定性好，所得复合镀层的硬度和耐磨性优于镍磷合金镀层。     

铝合金基体上多层组合镀层的耐蚀性研究

本文结合电化学腐蚀原理及产品实际使用环境,在镍-磷合金/金双镀层基础上建立了镍-磷合金/铜/镍-磷合金/金的多层组合镀层,分析了多层组合镀层的腐蚀机理,并对其耐蚀性能进行了验证。结果表明,镍-磷合金/铜/镍-磷合金/金的多层组合镀层可满足航空产品耐192 h盐雾腐蚀的使用要求,可有效提高材料的防护性能。     

镍—钨—磷／聚四氟乙烯复合刷镀工艺及性能研究

研究了镍－钨－磷／聚四氟乙烯电刷镀的工艺,刷镀液相成,研究了热处理条件对镍－钨－磷／聚四氟乙烯复合镀层的硬度及磨损率的影响。确定了复合镀层摩擦学特征最好的热处理温度和复合镀层聚四氟乙烯（PTFE）含量,通过研究发现,复合镀层中添加聚四氟乙烯（PTFE）,能显著降低磨损率,大大提高镀层的耐磨性,论述了采用电刷镀技术使基体材料形成一层具有弥散硬质相及自润滑减摩组分的聚四氟乙烯（PTFE）复合镀层。     

复合电沉积铜-钨合金工艺及其机理的研究

分析了阴极电流密度、微粒的质量浓度、温度、搅拌速率等对铜-钨复合镀层中钨微粒的体积分数的影响。用扫描电镜观察正交优化工艺制备的复合镀层,结果表明:镀层电沉积结晶均匀、细致。此外,对复合电沉积铜-钨的过程机理进行了初步探讨,结果表明:在低电流密度条件下,铜-钨复合镀层的沉积遵循Guglielmi模型机理。     

钛铜合金接插件连续电镀及化学镀高磷镍工艺优化

针对智能手机零件的无磁性要求，采用钛铜合金为基材进行电镀和化学镀高磷镍。通过正交试验对镀前阳极电解脱脂、阴极电化学浸蚀、冲击镀镍，电镀高磷镍和化学镀高磷镍，以及镀后封孔工艺进行优化。研究了镀层P含量对其磁导率的影响，得出镀层P质量分数至少为11%方可满足静态磁导率小于1.003H/m的要求。目前该连续电镀及化学镀高磷镍工艺已用于实际生产，产品合格率高达99.8%以上。     

自催化(无电解)镀Ni-W-P合金

本文介绍了通过改变柠檬酸钠(Na_3 C_6 H_5 O_7) 和钨酸钠(Na_2 WO_4) 的浓度,研究自催化(无电解)镀镍-钨-磷(Ni-W-P)合金的槽液成份和操作条件。3～4%(重量比)的钨与镍的共沉积,使镀层中磷含量由8. 9%降到2. 3%(重量比),其结果改善了这种镀层的结晶性。降低磷含量能增加这种镀层的残余应力和导电率。     

无电解镀镍-磷-氟化石墨分散镀层及其在模具上的应用

在无电解镀镍-磷合金溶液中加入特殊的分散剂和氟化石墨微粒,采用特殊的搅拌方式。可获得含氟化石墨9％(体积百分比)左右的镍-磷-氟化石墨分散镀层。从镀层截面与正面的显微镜照片上可清楚地看到该镀层中嵌有的氟化石墨微粒。该镀层的静摩擦系数(与硅橡胶块对磨)比铜(相同摩擦条件下)低一倍。将该镀层用于浇制硅橡胶母模的铜制公模上,获得了很好的脱模性。     

镍-钨-碳化硅非晶复合刷镀工艺的研究

为进一步提高非晶态镍－钨合金镀层的硬度,耐磨和耐蚀性能,在镍－钨刷镀液中加入适量碳化硅微粒,共沉积制得含碳化硅26．0－21．3％（质量分数）的非晶态镍－钨－碳化硅复合镀层。利用X射线衍射技术分析了所得镍－钨－碳化硅镀层的结构,研究了镀层中碳化硅含量,热处理温度复合镀层硬度,耐磨性和抗高温氧化性的影响。结果表明：碳化硅的弥散强化作用和热处理能显著提高复合镀层的硬度,耐磨性和抗高温氧化性。     

KF—B2O3—K2WO4熔盐体系中电镀钨的研究

对KF-B_2O_3-K_2WO_4熔盐体系的电镀钨工艺进行了详细研究。实验条件如下,温度:770～990℃,K_2WO_4浓度:9～20m/o,基体材料:钼、铜、镍和不锈钢。实验结果表明:在较高温度(T=850～900℃)和较低阴极电流密度下可获得平整光滑、呈银灰色的钨镀层。XRD分析表明,钨沉积过程中形成的织构方向与基体材料有关。     

HEDP溶液钢铁基体镀铜工艺的研究

采用赫尔槽试验和直流电解方法研究了HEDP镀液在钢铁基体上预镀铜的工艺过程,给出了最优镀液组成和最佳工艺条件:Cu2+10g/L,HEDP 160g/L,K2CO 360g/L,pH9.0,温度50°C,通气搅拌,阴极电流密度2A/dm2。试验结果表明,上述HEDP镀液组成简单、容易维护,不加任何添加剂的平均分散能力为62.21%,深镀能力为100%;可操作的阴极电流密度范围较宽,阴极电流密度为2A/dm2时的镀速达0.37μm/min;得到的半光亮铜镀层结合力良好、结晶细致。     

硫酸锰沉淀法制备重质碳酸锰的工艺研究

随着锂电池行业特别是动力锂电行业的迅速发展,作为重要基础锰源材料的重质碳酸锰受到高度重视。采用自主设计制作的沉锰反应器,进行硫酸锰沉淀法制备重质碳酸锰,最优工艺条件是反应温度45℃,反应时间10h,碳酸氢铵过量系数为1.05,产品碳酸锰的振实密度可达2.4g/cm3。在粒径控制剂存在的条件下,得到的重质碳酸锰粒径分布好,为高品质化学二氧化锰、高品质四氧化三锰的制备创造了条件,是锂电池正极材料的理想锰源材料。     

电解二氧化锰生产中铜含量偏高的原因分析及措施

针对电解二氧化锰生产中产品和电解废液中铜含量偏高的问题,分析其原因,提出相应的改进措施,使铜含量控制在一个较低的水平,产品质量大大提高。     

二氧化碳在P^＋／P—Si半导体电极上光电化学还原的研究

1870年,Royer使用Zn电极将CO_2还原为HCOOH。近年来,人们对CO_2在几十种金属电极上的电化学还原进行了深入的研究。但普遍存在的问题是CO_2在金属电极上还原的过电位较大,导致耗电较多。而半导体电极能吸收光能降低CO_2还原的过电位,所以人们对CO_2在半导体电极上的光电还原进行了探讨,使用的光阴极材料有P-GaP,P-GaAs,P-InP,P-CdTe。半导体Si的禁带宽度E_g=1.12eV,     

氯盐溶液锌——二氧化锰同槽隔膜电解的研究

通过实验对氯盐溶液体系锌—二氧化锰同槽隔膜电解的可行性进行了研究,并探讨了各主要影响因素如电流密度、温度、酸度等对电流效率的影响,得出自锌、锰氯化物溶液中同时电解得到电解锌和化学二氧化锰的较佳工艺条件。     

Electrochemical deposition and characterization of NiFe coatings as electrocatalytic materials for alkaline water electrolysis

In this study, nickel (Cu/Ni), iron (Cu/Fe) and nickel-iron (Cu/NiFe) composite coatings with various chemical compositions were electrochemically deposited on a copper electrode and characterized using cyclic voltammetry (CV), atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques in view of their possible applications as electrocatalytic materials for the hydrogen evolution reaction (HER) in an alkaline medium. The electrocatalytic activity of the coatings for the HER was studied in 1 M KOH solution using cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. The presence of nickel along with iron increases the electrocatalytic activity of the electrode for the HER when compared to nickel and iron coatings individually. The HER activity of the composite coatings depends on the chemical composition of the alloys. The Cu/NiFe-3 electrode (with a molar concentration ratio of Ni²⁺:Fe²⁺ of 4:6 in the plating bath) was found to be the best suitable cathode material for the HER in an alkaline medium under the experimental conditions studied. Furthermore, the electrocatalytic activity of the Cu/NiFe-3 electrode for the HER was tested for extended periods of time in order to evaluate the change in the electrocatalytic activity of the electrode with operation time. The HER was activation controlled and has not been changed after electrolysis. A constant current density of 100 mA cm⁻² was applied to the electrolysis system, and the corrosion behavior of the Cu/NiFe-3 electrode was investigated after different operation times using EIS and linear polarization resistance (LPR) techniques. For comparison, the corrosion behavior of a Cu/NiFe-3 electrode to which current was not applied was also investigated. The corrosion tests showed that the corrosion resistance of the Cu/NiFe-3 cathode changed when a cathodic current was applied to the electrolysis system.     

聚苯胺/二氧化锰复合材料的制备及其光催化性能

以二氧化锰为模板,采用原位复合法合成聚苯胺/二氧化锰复合材料(PANI/Mn O2)。采用IR和XRD对产物进行表征,结果表明,复合材料中的聚苯胺是理想的翠绿亚胺结构,二氧化锰为四方晶系α-Mn O2。研究光催化剂用量、染料浓度和催化剂重复使用次数对光催化降解直接耐晒翠蓝的影响,结果表明,在染料直接耐晒翠蓝浓度10 mg·L-1、PANI/Mn O2催化剂用量0.010 g·(20 m L)-1和光照20 min条件下,直接耐晒翠蓝降解率达84.1%。     

Cu修饰的多孔碳材料高效电化学还原CO2为CO

将二氧化碳电化学还原为一氧化碳是一种实现碳循环和利用的有效途径。为了利用大量过剩的二氧化碳资源,本文制备了一种简单合成的电催化剂,以生物质壳聚糖为前体制备了含氮多孔碳基底,嵌入均匀分布的非贵金属铜纳米颗粒进行修饰,通过调节铜的负载量,达到充分利用铜金属的活性,从而在电化学二氧化碳还原过程中实现了优异的一氧化碳法拉第效率和选择性。在-0.6V vs. RHE时下,一氧化碳的最大法拉第效率（FE）为78%,并且没有其他有效产物的生成,从而一氧化碳的选择性达到了100%,电流密度为1.9mA/cm²。并且在0.1mol/L KHCO₃水溶液中连续电解13h以上,一氧化碳的法拉第效率和选择性基本保持不变,制备的电极材料具有优异的稳定性。     

Activation studies on titanium anodes used in MnO2 electrodeposition

Titanium anodes from the electrolysis of electrolytic manganese dioxide (EMD) were activated chemically and electrochemically. The surfaces of activated and nonactivated titanium were characterized. Unlike nonactivated titanium, activated titanium evolved hydrogen and displayed a steady open circuit voltage. Hydrides precipitated on both activated and nonactivated surfaces. The passivating film grown on the anode during EMD deposition thinned during partial cathodic reduction and changed in composition from TiO₂ to TiO _x . Titanium anodes precoated with a thin layer of MnO₂ showed a delay in cathodic activation proportionally to the thickness of the precoat. A considerable difference in hydrogen diffusivity through thin and thick precoats is inferred from the time delay to activate the titanium surface.     

Material problems encountered in anodic MnO2 deposition

The characteristic material problems in electrolytic manganese dioxide (EMD) deposition concern the electrolysis cell components and, especially, the anodes. Temperature, sulphuric acid concentration, and current density are the most critical parameters which determine the corrosion and life times of the lead, graphite or titanium anodes. The corrosion of lead, even under the cover of electrodeposited manganese dioxide, pollutes the technical product. Graphite anodes are slowly oxidized, a process which limits their life time. The behaviour of titatanium as anode material is determined by the conductivities of the TiO _x interlayer as well as of the manganese dioxide deposits in the layered system Ti–TiO _x MnO₂. Passivation and depassivation reactions in conventional EMD electrolysis are described and the improved behaviour of titanium anodes in the suspension bath process is explained.Paper presented at the meeting on Materials Problems and Material Sciences in Electrochemical Engineering Practice organised by the Working Party on Electrochemical Engineering of the European Federation of Chemical Engineers held at Maastricht. The Netherlands, September 17th and 18th 1987.