由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，与硫酸盐电解液相比，从氨基磺酸盐电解液中沉积的Ｎｉ－Ｃｏ合金硬度高、内应力低。     

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。     

脉冲镀Ni-Co合金镀层内应力及钴含量的研究

研究了脉冲镀Ni-Co合金的工艺,讨论了脉冲电镀中占空比及频率对镀层内应力及钴含量的影响.实验结果表明:镀层内应力随占空比的增加而降低,随脉冲峰值电流密度增加而升高,随温度的升高而降低.镀层中Co的质量分数则随温度的升高而升高.     

添加剂对喷射电沉积纳米晶Co-Ni合金的影响

在氯化镍-硫酸钴体系电解液中采用添加剂喷射电沉积纳米晶Co-Ni合金,测定了其阴极极化曲线.研究了添加剂对阴极过电位、电流效率、镀层中Co含量、镀层的相结构、晶粒尺寸、表面形貌及显微硬度、软磁性能等影响.结果表明:添加剂增加了极化作用,影响了Co、Ni电沉积的动力学过程.当添加剂为2.5g/L时,与未加添加剂相比较,阴极过电位从3.594V增大到4.755 V,电流效率和沉积层中Co含量变化不大,但沉积层晶粒尺寸从12.8 nm明显降低到5.5 nm,维氏硬度从423升高到511,同时Co-Ni合金的软磁性能得以提高.     

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。     

电镀Ni-Co合金镀层耐腐蚀性能研究

电镀Ni-Co合金具有优良的高温耐腐蚀性能,被广泛的应用于生产实践中。研究了Co对Ni-Co合金镀层耐腐蚀性能的影响,并采用扫描电子显微镜对镀层的表面形貌进行表征。阳极极化、交流阻抗及浸泡试验结果表明,在10%硫酸、10%HCl及人工海水中,Ni-Co合金镀层耐腐蚀性随着Co含量的升高逐渐提高。说明Co含量的提高有利于提升镀层耐腐蚀性能。     

复合材料模具表面电铸镍钴合金研究

采用氨基磺酸镍镀液作为电铸的研究体系,并在镀液中加入氨基磺酸钴,对镍钴合金电铸层的内应力、组成、硬度、抗拉强度等进行了测试。结果表明,金属在沉积层中的含量与沉积速度有关,沉积速度与交换电流密度有关;当Co2 质量浓度为8 g/L,pH 3.5~4.4,电铸温度50℃,电流密度6 A/dm2时,得到的电铸层硬度为570HV,抗拉强度为1 487 MPa。     

喷射电沉积块体纳米晶Co-Ni合金工艺的研究

利用扫描电子显微镜（SEM），能谱仪（EDS）及X射线衍射（XRD）等分析方法研究了工艺参数对电解液喷射电沉积法制备块体纳米晶Co-Ni合金沉积层成分及结构的影响。结果表明；在本实验条件下，随电解液喷射速度的增加，沉积层中钴含量增加，而晶粒尺寸减小；随电解液温度的升高，沉积层中钴含量减小到一定值后增大，晶粒尺寸呈相反的趋势。沉积层的表面形貌为胞状结构。     

精密模具电铸镍钴工艺的研究

研究了Ni-Co电铸溶液成分和工艺参数对Ni-Co电铸层内应力、硬度、抗拉强度及延伸率的影响,提出了电铸液各成分含量和工作条件的最佳值.由本电铸工艺所得电铸层的硬度≥752Hv,抗拉强度≥1533N/mm~2,延伸率≥2.8%,杯突值≥4.3mm.     

四硼酸钠对Ni-Co合金镀层的影响

为提高Ni-Co合金镀层硬度,采用单因素实验研究四硼酸钠对Ni-Co合金镀层硬度的影响,利用硬度测试考察Ni-Co合金镀层硬度的变化,采用金相显微镜对镀层微观形貌进行分析,通过X-射线衍射及能谱分析镀层的相组成和成分,采用电化学测试考察复合镀层耐蚀性。结果表明,当溶液中加入四硼酸钠时,Ni-Co合金镀层中的镍、钴发生变化,镍增加,钴减低,当四硼酸钠为15 g/L时镀层晶粒更加细致,外观表面更加光亮,镀层表面形貌达到最佳;腐蚀电流为9.422μA,硬度达到467.4 HV。     

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。     

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。     

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%。     

化学镀Ni-W-B非晶质电阻膜的研究

研究了化学懂Ni-W－B合金的工艺及性能．结果表明，在Ni-B槽液中加入一定量的钨酸钠溶液，不仅能得到含钨、硼的镀层，而且还能提高镀液的沉积速度；Ni-W-B合金层在镀态时为非晶态结构，它的电阻率随钨含量的增加而增大，随镀层厚度的增加而降低．     

The effect of pulse-reverse electroplating bath temperature on the wear/corrosion response of Ni-Co/tungsten carbide nanocomposite coating during layer deposition

In this article, the effect of bath temperature during layer deposition on the electrochemical/abrasion responses of Ni-Co/tungsten carbide nanocomposite coating has been investigated. The Ni-Co/tungsten carbide nanocomposite coating was obtained using simultaneous deposition of tungsten carbide nanoparticles in three Ni-Co bath temperatures of 20, 40, and 60?°C. Afterwards, in order to characterize the obtained coatings, Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM), X-Ray diffraction (XRD), MAP analysis, potentiodynamic polarization and electrochemical impedance spectroscopy methods in 3.5?wt% NaCl, and also abrasion test using a pin on disc method were carried out. The results of this study revealed that the deposition obtained from Ni-Co bath contains tungsten carbide nanoparticles and results in strong (200) and hard (111) textures in the coating at different temperatures. Also increasing the bath temperature from 20 to 40?°C results in the absorption of cobalt and tungsten carbide nanoparticles, as well as reducing the nickel content and corrosion resistance in the coating, and on one hand it increases the abrasion resistance of the coating. However, a bath-temperature increase from 40 to 60?°C results in reducing the absorption of cobalt and tungsten carbide nanoparticles, and increasing the nickel content and corrosion resistance in the coating as well as reducing the abrasion resistance of the coating.     

High-speed jet electrodeposition and microstructure of nanocrystalline Ni-Co alloys

The jet electrodeposition from watts baths with a device of electrolyte jet was carried out to prepare nano-crystalline cobalt-nickel alloys. The influence of the concentration of Co²⁺ ions in the electrolyte and electrolysis parameters, such as the cathodic current density, the temperature as well as the electrolyte jet speed, on the chemistry and microstructure of Ni-Co-deposit alloys were investigated. Experimental results indicated that increasing the Co²⁺ ions concentration in the bath, the electrolyte jet speed and decreasing of the cathodic current density and decrease of the electrolyte temperature all results in an increase of cobalt content in the alloy. Detailed microstructure changes upon the changes of alloy composition and experimental conditions were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD results show the Ni-Co solid solution was formed through the jet electrodeposition. Phase constitution of solid solution changes progressively under different electrolyte concentration. Alloys with low Co concentration exhibit single phase of face-centered cubic (fcc) structure; The Co concentration over 60.39 wt.%, the alloys are composed of face-centered cubic (fcc) phase and hexagonal close-packed (hcp) phase. Furthermore, the formation of the nanostructured Ni-Co alloy deposit is investigated. Increasing the Co²⁺ ions concentration in the bath, the cathodic current density, the electrolyte temperature and the electrolyte jet speed all result in the finer grains in the deposits. Additives such as saccharin in the electrolyte also favor the formation of the finer grains in the alloy deposits.     

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.     

峰值电流密度对脉冲镀镍钴合金纳米镀层机械性能的影响

研究了峰值电流密度对脉冲镍钴合金纳米镀层的成分、晶粒尺寸、显微硬度、抗拉强度的影响.结果发现:在一定范围内,峰值电流密度的增大,可以降低镀层钴含量、表面粗糙度和晶粒尺寸,使菜花胞状结构更明显,提高镀层显微硬度(最高可达600 kg/mm2)和抗拉强度(最高可达1 200 MPa).然而,峰值电流密度太大又会使显微硬度和强度下降.与采用类似方法制得的纯镍纳米镀层相比,镍钴镀层的显微硬度并未明显升高.这说明在该纳米材料中,固溶强化效果并不很明显,而以细晶强化为主.