Nickel Electroplating

NICKEL ELECTROPLATING has been practicallyused for decades.There is an unknown part in theplating,although this is easy to plate.Applications ofthe plating are described from the practical viewpoint.Purpose of Nickel Electroplating(1)Decorative,and corrosion resistanceNickel electroplating is deposited on iron,cupper,zinc and aluminum substrate etc.,and chromiumplating is usually deposited on nickel plating.Hexavalent chromium plating has an important effecton the corrosion resisitan…     

电镀/化学镀双层镍的研究

在45学镀Ni-P合金层进行对比,采用中性盐水、酸性盐水和浓盐酸浸泡实验考查了镀层的耐蚀性能,采用热震实验和锉刀实验考查了镀层的结合强度,并分析了镀层的表面形貌和硬度.结果表明:电镀/化学镀双层镍在较薄时就具有与单层Ni-P合金镀镍层相当的耐蚀性能,且与钢基体结合良好.     

Electroplating of Co-Fe alloys from Aqueous Sulphate Baths

Earlier work on the electroplating of cobalt and iron individually has been extended to the electroplating of Co-Fe alloys from sulphate—based baths containing in: 0.10–0.20 CoSO₄.7H₂O, 0.20–0.10 FeSO₄.7H₂O, 0.10 H₃BO₃ and 0.10 mol l^?1 Na₂SO₄.10H₂O in addition to 3 g/l-1 sodium potassium tartrate, at pH 3.4. The alloy deposition was attended by a lower polarization than either of the parent metals from baths of similar composition, except for the absence of the other depositable metal ion, indicating the formation of Co-Fe solid solution. Moreover, the less noble metal (Fe) deposits in the alloy preferentially, pointing to alloy plating of the anomalous type. A comparison between the experimental and the actual (calculated) polarization curves during codeposition was utilized to provide an explanation of the anomalous phenomenon. Under identical conditions of current density (1 Adm^?2), duration (20 min) and temperature (25 °C), the current efficiency (f) of the alloy plating (44%) and the percentage throwing power (TP) of the bath (11%) were much lower than those observed for either of the parent metals (f≥ 88% and TP ≥21%). On the other hand, the Vickers microhardness of the alloy (447) is somewhat higher than that for cobalt (415) or iron (434 kgf mm^?2). Moreover, the microhardness of the alloy could be further increased by increasing the iron content of the alloy. Despite the low content of cobalt (20%), the surface morphology of the alloy is similar to that to cobalt.     

槽边循环电解法回收电镀废水中Ni的研究

对槽边循环电解法回收电镀废水中Ni进行了分阶段实验研究,包括小型试验、扩大试验以及系统扩大试验。试验结果表明,适合工业生产中使用的操作条件如下：Ni离子浓度可在0．5～2．5/L变化,电流密度40～80A／m^2,槽电压3—6V,pH=4．5～5．5;当Ni离子浓度保持在1．0～2．5g／L,若连续操作电流密度采用100～150A／^2,则电流效率仍大于40％;若从高浓度操作到低浓度,每次回收到0．5/L,电流密度应取40～80A／^2,操作10次后,可回收到使浓度小于0．1g／L,弃掉,则回收槽的回收率大于99％;由3类不同规模试验的对比中可以看出,在相同条件下,电流效率几乎相等。研究表明,采用槽边循环电解法回收电镀废水中的Ni是完全可行的,且可保证较高回收效率。     

The Haring-Blum Cell

The concept of Throwing Power is explained, as an empirical expression for the differences in electrodeposited metal thickness at sites nearer to and further from the anode. Its measurement using the Haring-Blum and other cells, is described. Means of interpreting such data are discussed using different published formulae.     

从废镍催化剂中提取镍生产硫酸镍

介绍了如何从废镍催化剂中提取镍，减少环境污染，降低硫酸镍的制造成本。     

电镀工艺对氨基磺酸盐体系镍镀层内应力的影响

目的 在氨基磺酸盐电镀体系中,探索出各电镀工艺参数对镀层内应力的影响规律.方法 采用一种改良的双阳极-阴极弯曲的办法测试镀层应力.通过X射线衍射实验(XRD)、扫描电子显微镜(SEM)以及KEYENCE数码显微系统,分别分析应力状态下镀层织构、微观畸变以及镀层形貌.结果 电流密度越大,镀层的张应力越大,当电流密度达到1...     

光电子器件外壳脉冲电镀镍钴合金工艺及其耐蚀性

目的开发一种脉冲电镀镍钴合金工艺,并研究其镀层的耐腐蚀性能,以期将其应用于光电子器件外壳电镀领域。方法采用脉冲电镀的方式获得电镀镍钴合金镀层,通过腐蚀失重试验、极化曲线测试以及电化学阻抗谱测试等方法考察镀层的耐腐蚀性能,通过场发射扫描电子显微镜、能谱仪和X射线衍射仪等设备对镀层的表面微观形貌、成分和晶体结构进行了表征,并与传统的电镀氨基磺酸镍工艺进行了抗腐蚀性能的比较。在耐腐蚀性能最优的工艺条件下,对公司某型号光电子器件外壳进行了镍钴合金电镀,并对产品的镀层进行一系列考核。结果随着Co含量的增加,脉冲电镀镍钴合金镀层的结晶更均匀致密,晶粒、镀层孔隙更小。在3.5%NaCl溶液中,随着Co含量的增加,脉冲电镀镍钴合金镀层的自腐蚀电位正移,自腐蚀电流密度减小,电荷转移电阻增加。Co含量25%的脉冲电镀镍钴合金镀层的自腐蚀电位和自腐蚀电流密度分别为-331 mV和2.26μA/cm~2,电荷转移电阻是212.62 kΩ。产品的镀层质量、引线涂敷强度、引线疲劳等考核均满足相关标准要求。结论脉冲电镀镍钴合金镀层的耐蚀性随着Co含量的增加而增强。在3.5%的NaCl溶液中,Ni-Co(25%)的镀层自腐蚀电流仅是Ni镀层的44%。开发的脉冲电镀镍钴合金工艺可以应用于光电子器件外壳电镀领域。     

电流密度和润湿剂对Ni镀层组织与形貌的影响

采用普通型瓦特液,按照不同的工艺参数在铜材表面电镀镍,通过SEM对镀层表面进行扫描观察和使用XRD测试对镀层表面进行检测,并且对不同样品数据进行对比和分析,从而达到研究电流密度及润湿剂对镀层沉积速度、表面显微形貌和晶粒尺寸的影响的目的.实验结果表明,电流密度的影响非常显著,不同电流密度下的镀层表面形貌和晶粒尺寸存在相应的差别.适量的润湿剂对镀层的沉积具有促进作用,对防止针孔的生成及细化晶粒具有明显的效果.     

ChCl-EG低共熔溶剂体系中镍沉积的电化学行为研究

目的 研究镍在低共熔溶剂体系中的电沉积、电化学行为及形核方式。方法 使用循环伏安法和计时电流法,研究在氯化胆碱-乙二醇（ChCl-EG）低共熔溶剂体系中镍沉积的电化学行为及其形核理论。 采用SEM测试手段对镍电沉积层的微观形貌进行观察和分析,同时采用EDS分析镍镀层的元素组成。 结果 ChCl-EG低共熔溶剂的电化学窗口为2.63 V,镍在ChCl-EG低共熔溶剂体系中的氧化、还原电位分别为0.79 V和-0.34 V。不同扫描速度的循环伏安曲线表明,在扫速为10~50 mV/s时,Ep与v无关,呈现出可逆反应的特性;而当扫速增加到50~90 mV/s时,Ep随v的增加而呈现负移的趋势,符合不可逆反应的特性。可以判断镍（Ⅱ）在ChCl-EG低共熔溶剂中属于准可逆反应。在“电流滞环”-1.00 ~ -1.08 V下测定计时电流曲线,通过拟合计时电流曲线与理论模型对比发现,镍（Ⅱ）在ChCl-EG体系中的电结晶过程符合Scharifker-Hill三维形核模型。镍电沉积层在铜基体上分布均匀,镀层中只含有镍元素。结论 镍（Ⅱ）在氯化胆碱-乙二醇低共熔溶剂中的电沉积过程是准可逆反应且形核机制为三维瞬时成核,通过ChCl-EG低共熔溶剂体系可以得到纯度高并且分布均匀的镍镀层,且镍镀层的颗粒尺寸为22.1 nm。     

Effect of the Current Density on Morphology,Porosity, and Tribological Properties of Electrodeposited Nickel on Copper

In the steel industry, nickel coating on copper has increased the lifespan of continuous ingot casting molds. The objective of this work is to estimate the porosity of nanocrystalline nickel electrodeposited onto copper. Characteristics of nickel coating such as hardness, wear resistance, porosity, morphology, and adhesion are very important for maximum performance of molds. The effective porosity in nickel coating was determined by using anodic voltammetry. The porosity of electrodeposited nickel onto copper increased from 0.16% up to 6.22% as the current density increased from 1.5 up to 8.0 A dm⁻². The morphology of the nickel electrodeposited at lower current densities was more compact. Tribological properties were studied using hardness measurements, and calotest. Results of calotest indicated a wear coefficient of 10⁻⁶ for all samples. An extremely low friction coefficient of 0.06-0.08 was obtained for the sample deposited with a current density of 1.5 A dm⁻², and a friction coefficient of 0.15-0.21 was measured for the nickel coating electrodeposited at a current density of 5 A dm⁻². Effects of the current density of the electrodeposition process on the morphology, porosity, and tribological properties were evaluated.     

Influence of Bath Compositions and Some Operating Conditions on the Electroplating of Cobalt from Aqueous Sulphate Baths

A systematic study has been made of the influence of aqueous sulphate bath constituents on the cathodic polarization curves during cobalt electrodeposition. The optimum bath composition has been established and it contains: 0.30 mol l^?1 CoSO₄.7 H₃0, 0.30 mol^?1 H₃BO₃. 0.05 mol l^?1 (NH₄)₂SO₄ and 0.10 mole l^?1 Na₂SO₄.10 H₂o. Cobalt electroplating from the optimized bath has been performed under a variety of conditions viz: pH, 1.5 to 5.3; current density, 0.2 to 2.0 A dm^?2 and temperature 25 to 53°C. Under the most suitable conditions, the optimum bath is characterized by a high cathodic efficiency (~ 99%), moderate throwing power (21.6%) and throwing index (1.47). The bath produced smooth, adherent and semibright plates characterized by a high microhardness (411.4 kgf mm^?2) and their morphologies, as revealed by scanning electron microscopy, showed a dependence on the plating variables.     

铝质材料上电镀镍及预处理工艺的研究

采用浸镀Ｚｎ－Ｎｉ合金预处理工艺,在铝质材料表面可制得结合力良好,外观平整光滑的镀镍层,与磷酸阳极氧化处理和二次浸锌处理相比,结晶更细致,镀层质量更好。添加剂能明显改善镀层质量。镀镍对铝质材料的表面改性效果明显。     

缓冲剂在电镀工业中的应用

着重叙述了缓冲剂原理及应用。详细阐述了在电镀工艺中如何选用缓冲剂以及将电镀中的缓冲剂与化学中的缓冲剂的应用加以区别。     

Electroplating zinc transition layer for electroless nickel plating on AM60 magnesium alloys

Electroplating zinc coating as transition layer of electroless nickel plating on AM60 magnesium alloys was investigated. The zinc film can be deposited in a pyrophosphate bath at 50-60 ℃ under current density of 0.5-1.5 A/dm^2. A new fore treatment technology was applied by acid cleaning with a solution containing molybdate and phosphorous acid, by alkaline cleaning in a bath containing molybdate and sodium hydroxide. The subsequent electroless plating was carried out in nickel sulfate bath. The SEM observation shows that the deposition is uniform and compact. The polarization curve measurements show that the corrosion potential of the zinc plating in 3.5% NaCl is about -1.3 V（vs SCE） which is noble than that of magnesium substrate. The zinc eleetroplating can be applied as the pretreatment process for electroless nickel plating on magnesium alloys.     

绿色电镀与清洁生产

电镀作为一种表面精饰工艺广泛应用于机械、电子、仪器、仪表、轻工、航天、军工等许多领域。但是传统的电镀工艺技术产生大量毒性较大的废水、废气和污泥，给环境造成了极大的污染。采用绿色电镀技术和清洁生产技术能最大程度的减少和消除传统电镀给环境带来的污染和危害。提出绿色电镀的内涵并较为详细的介绍了绿色电镀和清洁生产技术。     

镍铁合金刷镀工艺的优化

就镍铁合金刷镀过程中电极相对运动速度、施镀电压、温度等参数对镀层光亮度、硬度和耐磨性的影响进行了试验,得知工艺参数配合关系的重要性。其中电极速度与施镀电压的配合,对光亮度和耐磨性的影响有决定性的作用;电极速度对耐磨性、电压对硬度、温度对光亮度的影响是第一位的。通过优化试验,提出了获得最佳光亮度,最高硬度和最高耐磨性镀层(与淬火45号钢相比)的施镀工艺。     

非水溶液电镀

叙述了各种类型的非水溶剂,及用于电镀溶液的非水溶剂必须具备的条件。例如,对欲沉积金属离子盐的溶解性;构成电镀溶液的导电件;溶剂本身的极化窗和施主性质等。还介绍了自非水溶液中镀铝、镍、铬和镍-铬合金的一些研究成果。     

Inorganic Chromatography on Cellulose: Some Applications to the Analysis of Electroplating Solutions with Special Reference to Nickel Plating Baths

The paper describes the technique of inorganic chromatography using paper strips and columns of cellulose pulp in combination with organic solvents, for the detection and determination of metals in electroplating baths. Special reference is made to nickel plating baths in which sulphate ion is present. It is shown that satisfactory separations can be achieved of a number of metals as chlorides, even in the presence of sulphates, providing acidity of the sample solution and organic solvent are carefully controlled. The following metals have been examined: Ni, Co, Fe, Cu, Mn, Cd, Cr, Al and Pb. The methods for final determination have also been described.