电氨基磺酸盐和硫酸盐电解液电沉积Ni—Co合金的对比研究

通过大量实验对比了氨基磺酸盐和硫酸盐两种电解液电沉积Ｎｉ－Ｃｏ合金Ｃｏ含量的影响因素，以及Ｎｉ－Ｃｏ合金沉积层的硬度、内应力与Ｃｏ含量的关系，结果表明，与硫酸盐民解液相比，从氨基磺酸盐电解液中沉积的Ｎｉ－Ｃｏ合金硬度高，内应力低。     

氨基磺酸盐电镀Ni-Fe合金层内应力的影响因素分析

实验探讨了氨基磺酸盐电沉积Ｎｉ－Ｆｅ合金层内应力的影响因素。结果表明,阴极电流密度、电解液温度、ｐＨ值,氨基磺酸镍的浓度,氯化亚铁的浓度以及添加剂的种类都影响Ｎｉ－Ｆｅ合金层的内应力,添加一定量的９７１添加剂可以使电沉积Ｎｉ－Ｆｅ合金层的内应力趋于零。     

电沉积Ni-Co梯度合金的研究

在以氨基磺酸镍和氨基硫酸钴为主盐的电解液中，镍作阳极，ｐＨ＝４．０，５５℃条件下，采用２Ａ／ｄｍ＾２的阴极电流密度，可以电沉积出积出钴含量随厚度而变化的Ｎｉ－Ｃｏ合金层。实验结果表明，随着通电量的增加，合金镀层中的钴含量不断下降。由镀层性能测试可以看出，随着通电量的增加，合金镀层的硬度，内应力减小。     

脉冲电镀Ni－Co合金的研究

研究了脉冲参数对电沉积Ｎｉ－Ｃｏ合金镀层的钴含量与硬度的影响。确定了最佳的脉冲参数。应用Ｘ射线和扫描电镜分析了Ｎｉ－ＣＯ合金镀层的结构和形貌。比较了脉冲电流（ＰＣ）和直流电流（ＤＣ）电镀Ｎｉ－Ｃｏ合金镀层的各种性能。     

电沉积Ni—Co合金及其结构研究

采用硫酸盐体系电沉积Ｎｉ－Ｃｏ合金，研究了电镀工艺参数对镀层组成及电流效率的影响，测定了镀层结构。实验发现：在Ｎｉ－Ｃｏ合金镀层中，当Ｃｏ含量低于７６ｗｔ％时，合金由两种面心立方结构的固溶体组成；Ｃｏ含量介于７６￣９０ｗｔ％之间时，由面心立方和六方密排两种结构的固溶体组成；Ｃｏ含量超过９０ｗｔ％时，合金只有一种立方密排结构的固溶体相成。     

电沉积Ni－Co合金及其结构研究

采用硫酸盐体系电沉积Ｎｉ－Ｃｏ合金，研究了电镀工艺参数对镀层组成及电流效率的影响，测定了镀层结构。实验发现：在Ｎｉ－Ｃｏ合金镀层中，当Ｃｏ含量低于７６ｗｔ％时，合金由两种面心立方结构的固溶体组成；Ｃｏ含量介于７６～９０ｗｔ％之间时，由面心立方和六方密排两种结构的固溶体组成；Ｃｏ含量超过９０ｗｔ％时，合金只由一种六方密排结构的固溶体相成。     

电沉积锌－镍－钴三元合金的研究

通过对镀液组成及电镀参数的研究，确定了电沉积Ｚｎ－Ｎｉ－Ｃｏ三元合金的工艺条件，获得的三元合金镀层其耐蚀性明显优于Ｚｎ－Ｎｉ合金镀层，且随钴含量增加耐蚀性增强。     

电沉积锌—镍—钴三元合金的研究

通过对镀液组成及电镀参数的研究，确定了电沉积Ｚｎ－Ｎｉ－Ｃｏ三元合金的工艺条件，获得的三元合金镀层其耐蚀性明显优于Ｚｎ－Ｎｉ合金镀层，且随钴含量增加耐蚀性增强。     

化学镀Co—W—P三元合金的研究

研究了镀液中各组分及ｐＨ值与镀层中钨、磷含量的关系，获得Ｃｏ７３Ｗ１６Ｐ１１合金镀支，并通过人工汗液浸泡试验比较了Ｃｏ－Ｗ－Ｐ合金镀层与不锈钢、Ｃｏ－Ｐ、Ｎｉ－Ｗ－Ｐ、Ｎｉ－Ｐ合金镀层的耐蚀性。     

钨的共沉积对化学镀镍层性能的影响

研究了共沉积钨对化学镀Ｎｉ－Ｐ合金结构和性能的影响，研究结果表明，Ｎｉ－Ｗ－Ｐ合金镀层的晶化程度主要由磷含量决定而与钨含量无关；钨的共沉积对镀层硬度影响不大；在相同含量的情况下，Ｎｉ－Ｗ－Ｐ合金镀层的耐蚀性，耐磨性和热稳定性能都优于Ｎｉ－Ｐ合金。     

电沉积Ni-Co合金的研究

研究了氨基磷酸盐电沉积Ni-Co合金电解液组成及工艺条件对沉积层中Co含量的影响.并测定了Ni-Co合金沉积层中Co含量与Ni-Co与硬度的关系,以及影响Ni-Co合金沉积层内应力的因素.实验结果表明,将一定量的Co引入Ni沉积层,可以显著地提高其硬度;当在电解液中添加一定量的Ni-1添加剂后,能使Ni-Co合金沉积层的内应力为零.这些有益的实验结果为电铸加工使用寿命长、机械性能好的模具提供了一定的依据.     

The role of anion additives in the electrodeposition of nickel-cobalt alloys from sulfamate electrolyte

Nickel-cobalt alloys have been deposited from sulfamate electrolyte with acetate and citrate-anion additives and evaluated for structure and properties, such as microhardness, tensile strength, internal stress and high-temperature oxidation. XRD data show that at low Co content, the alloys exhibit face-centered cubic (fcc) growth orientations. Above 60% Co, the deposit is completely hexagonal close packed (hcp) with pronounced (100) and (110) lines. It seems likely that the Ni-Co deposits from typical sulfamate electrolyte at pH 5, as well as at current density higher than 5 A/dm², include metal hydroxides. This is followed by the formation of a more strained structure. The high-temperature oxidation rate of the Ni-Co coating from sulfamate electrolyte at pH 5 is twice that of the alloy deposited from the electrolyte with anion additives. We believe that, citrate complexes of Ni and Co, which are assumed to be involved in alloy deposition, eliminate the incorporation of hydroxides into the deposits and enable low-internal-stress coating. The anion-modified bath offers stability of structure and properties of the alloy over a wide range of acidity and current density.     

Properties and microstructure of nickel electrodeposited from a sulfamate bath containing ammonium ions

A 70 m thick Ni layer was electrodeposited from a sulfamate bath containing various amounts of ammonium ions onto a copper plate. The detailed microstructure of the Ni deposits was characterized using a plane-view and cross-sectional transmission electron microscopy (TEM). The textures of the Ni deposits were also determined using conventional X-ray diffraction. Experimental results indicated that ammonium ions suppressed the lateral growth of Ni deposits and favoured out growth, thus leading to the growth of [1 1 0] and [3 1 0] oriented deposits. A structural refinement effect was observed after ammonium ions were added to the sulfamate bath. Ammonium ions also increased the internal stress and hardness of the deposits. A general Hall–Petch relationship was observed for the dependence of deposit hardness on the average grain size of the Ni deposits. The adsorption of atomic hydrogen and the polar NH₃ molecule explains the effect of ammonium ions on the electrocrystallization of Ni.     

Ni-Co-C代硬铬镀层的制备及性能研究(Ⅰ):镀液组成及工艺优化

为提高Ni-Co合金镀层的致密性、硬度、耐磨性和耐蚀性等各方面性能,采用电沉积方法在镀层中引入原子态的碳。对Ni-Co-C代铬镀液中可能的碳源进行了筛选,并利用单因素试验对镀液中各组分的含量及工艺条件进行了优化,最终确定了草酸铵-柠檬酸铵体系为Ni-Co-C代铬镀液体系。得到的镀层外观与暗镍类似,结晶较细,平整性和均匀性稍差。优化的Ni-Co-C基础镀液稳定性好,长期放置不结晶、不沉淀;阴极电流效率稳定在45%~48%。     

脉冲电沉积钴镍合金及其生长形态的研究

研究了钴镍合金渡液中mCO^2 /(mCO^2 mNi^2 )对镀液中钴含量的影响。利用XJG－05金相显微镜观察了镀层表面形貌及截面生长状态。结果表明：合金镀层中的钴含量随着mCO^2 /(mCO^2 mNi^2 )的增大而显著增大。电位较负的钴先沉积，为异常共沉积。脉冲条件下所得镀层致密、均匀，呈胞状生长。     

符合RoHS、ELV欧盟指令的环保化学镀镍工艺

为了顺应RoHS、ELV指令的要求,开发了无铅/镉化学镀镍工艺。从镀层合金成分、中性盐雾实验、硬度、耐磨性、整平性、内应力、微观形貌、镀速、镀液稳定性和含磷量等方面与中磷化学镀镍工艺进行了比较。结果表明,无铅/镉化学镀镍工艺镀液更稳定,所得的镍镀层内应力稍高;硬度、耐蚀性、可焊性、附着力等性能相当;而耐磨性、耐污性、沉积速度和含磷量均高于中磷化学镀镍工艺,尤其是镀层亮度、微观结构和整平效应表现更优。     

Electrodeposition of Ni–Co alloys from sulfamate baths

The paper describes the results of electrochemical investigations of Ni–Co deposition from a sulfamate bath in the presence of boric acid and two additives. The individual deposition of nickel was shown to be partly inhibited by the adsorption of sulfamate ions at low polarization; such inhibition was not observed for cobalt. The introduction of saccharin at 100 ppm, with a wetting agent seems to hinder sulfamate adsorption and Ni deposition departs at less cathodic potentials. The presence of cobalt has no effect on nickel deposition, whereas cobalt deposition is hindered by the presence of nickel in the bath. Galvanostatic deposition was carried out at the surface of a RDE and with a rotating cylinder Hull cell. At low current densities deposits with a Co content of approx. 40% were produced, but this content was shown to decrease with the applied current density. Examination of experimental data showed that cobalt deposition is diffusion-controlled and that Co content decreases with the applied current density relative to the limiting current density.     

Electrodeposition of Zn-Co alloys with pulse containing reverse current

The electrodeposition of Zn-Co alloy deposits was studied by means of pulse-plating technique. The surface morphologies of Zn-Co alloy deposits were examined using scanning electron microscopy (SEM), and an attendant energy dispersive X-ray analyser (EDA) was used to analyse the composition of Zn-Co alloy deposits. Results obtained showed that the average current density and reverse current density amongst all the variables investigated had very strong effects on the cobalt content in the Zn-Co alloy deposits. It is possible to electrodeposit Zn-Co alloy coatings with a very wide cobalt content range of 10-90 wt.% by modulating pulse parameters. Grain size, surface appearance and internal stress in the deposits were also improved significantly by introducing reverse current.     

电沉积无铅可焊性锡铋合金的研究

提出了一种酸性锡铋合金电沉积工艺。研究了镀液中硫酸铋含量和电流密度对镀层铋含量、电流效率及镀层表面形貌的影响，另外，通过循环伏安曲线的测量研究了锡铋合金的电沉积过程，结果表明，镀层铋含量随硫酸铋含量的增大而增大，铋在-0.3V时开始析出，当电位达到-0.6V时，锡和铋共同沉积。