含硫添加主一对电铸镍沉积层组织和性能的影响

研究了硫酸盐镍电镀液的组成及浓度，特别是糖精添加剂含量对电铸镍沉积层组织形貌和性能的影响。     

糖精含量对电沉积镍电化学行为的影响

为了进一步弄清糖精对镍电沉积层的细化作用,利用动电位扫描与交流阻抗法,研究了不同浓度的糖精对4N．OFC高纯铜片在Watts镀液中电沉积镍电化学行为的影响。结果表明,在Watts镀液中添加糖精可增大阴极极化,并使电化学反应电阻增大,有利于晶粒细化。     

酸性柠檬酸盐溶液电镀镍

几乎所有的镀镍溶液都用硼酸作缓冲剂,但含硼化合物毒性高。研制了一种适合于电沉积镍的新型电镀溶液,镀液中柠檬酸钠充当缓冲剂和络合剂,这种镀液的缓冲容量比传统Watts大。研究了柠檬酸钠对阴极极化曲线、阴极电流效率、镀液分散因子的影响。用扫描电镜检查:镍沉积层致密、针孔少、结晶细小,X射线分析结果表明,与从Watts镀液中得到的镍沉积层比,从柠檬酸钠镀液中得到的镍沉积层晶粒小,晶面取向随机。因此,在Watts电镀液中,柠檬酸钠是硼酸的有效替代品。     

高硫镍镀液中苯亚磺酸钠的测定

准确测定电镀液中添加剂的含量,对排除电镀故障及提高镀液质量有指导作用.采用紫外分光光度法研究了pH值、无机盐等对高硫镍镀液中苯亚磺酸钠吸光度的影响,建立了测定镀液中苯亚磺酸钠浓度的分析方法.结果表明,该方法快速、准确,可用于工业电镀高硫镍电解液中苯亚磺酸钠浓度的现场分析.     

光亮镀镍电解液中糖精的去除研究

采用紫外分光光度法考察了双氧水、高锰酸钾对光亮镀镍体系中添加剂糖精的去除效果,并进一步研究了时间、温度和活性炭添加量对光亮镀镍液中糖精去除的定量结米.结果表明:采用双氧水、高锰酸钾氧化不能有效去除糖精;而活性炭则能通过吸附有效去除电镀液中的糖精,但处理时间和温度对去效果影响不大;当镀液糖精浓度为1g/L时,1 g粉状活性炭最多可吸附除去0.22 g糖精.     

锌镍合金电镀工艺研究

通过正交试验方法,采用新的添加剂和配位剂实现了锌镍合金电镀,优选出了新的锌镍合金电沉积工艺和镀液配方.通过GDA-750型辉光放电光谱仪、HitachiS-570型扫描电镜等分析手段,研究了不同电镀工艺参数对镀层中镍含量、镀层厚度和镀层外观的影响规律.采用了电化学试验法研究了镍含量变化对镀层的耐腐蚀性的影响.结果表明:通过此新型的镀液配方和工艺条件,可获得含镍9%～13%、具有良好外观和耐蚀性好的锌镍合金镀层.随着电流密度的增加,镀层中镍含量先减小后增加;随着温度和pH值的增加,镀层中镍含量在不断增加;镀层的自腐蚀电位随着镍含量的增加,呈现先变正后变负的趋势,镍的含量为12%～13%时,合金的自腐蚀电位最正.     

脉冲电沉积纳米晶镍沉积层的力学性能研究

为了提高镍沉积层的显微硬度和抗拉强度,采用传统的Watt镀液通过脉冲电沉积制得纳米镍沉积层.通过扫描电镜(SEM)、X射线衍射(XRD)方法分析了沉积层的表面形貌、织构和晶粒大小与脉冲参数的关系.分析表明,微观形貌为胞状结构,平均晶粒尺寸为10.3 nm;随着占空比减小,晶粒得以细化.研究了脉冲参数对纳米镍镀层显微硬度、抗拉强度的影响,最大显微硬度达到591 HV,最大拉伸强度达900MPa,分别为直流镍镀层的4.0和1.4倍;热处理试验表明,200℃热处理有利于提高镍镀层的显微硬度.     

镍-铁-磷/金刚石复合沉积工艺与性能研究

以三元合金为基体的复合电沉积层综合了一般耐磨镀层的性能和所镶嵌的固体微粒的性能.为开发新型多元非晶态合金耐磨复合沉积层,以复合沉积层耐磨减摩性为主要衡量指标并综合考虑其他性能指标,用正交试验法进行了镍-铁-磷/金刚石复合电沉积工艺与性能的研究.结果表明,在试验所采用的复合电沉积工艺控制范围内,可获得金刚石微粒弥散分布的镍-铁-磷/金刚石复合电沉积层,通过调整沉积工艺参数,能得到不同金刚石微粒复合量的复合电沉积层;在镀态下该复合沉积层(基质)呈非晶态结构;较佳综合性能复合层的电沉积工艺参数为:镀液中金刚石微粒(0.5～1.0 μm)含量6 g/L;NaH2PO2·H2O含量2 g/L;FeSO4·7H2O含量70 g/L,其对制备具有良好摩擦学特性的镍-铁-磷/金刚石复合沉积层具有重要的参考价值.     

镍钴合金电沉积中硫酸钴影响的探讨

电沉积镍层硬度低,耐磨性差,在瓦特型镀镍液中加入硫酸钴可以提高镀层的抗热性能、耐蚀性能和韧性.采用硫酸盐电解液电沉积镍钴合金,研究了电解液中硫酸钴浓度与镀液分散能力、深镀能力的关系及其对镀层显微硬度、孔隙率和内应力的影响.同时,利用扫描电子显微镜分析了沉积层的表面形貌.结果表明:随着镀液中硫酸钴浓度的增大,镀液的分散能力下降,深镀能力升高;镀层显微硬度显著提高,内应力和孔隙率也有所增加.镍钴合金沉积层比纯镍镀层更细致、结晶均匀.     

锌镍合金电镀

本文确定了锌镍合金电镀液中硫酸镍及葡萄糖酸钠的含量,得到了较优配方,测定丁不同电流密度下电镀锌镍合金镀层中的锌、镍含量,获得了较宽的电流密度范围(2.5A/dm~2～11A/dm~2)和含镍10～15%的锌镍镀层.     

Effect of deposition parameters on microstructure of electrodeposited nickel thin films

Nickel thin films were prepared using electrodeposition process on a copper substrate. The effect of deposition parameters on film microstructure has been investigated with and without an organic additive (saccharin). Electrodeposition has been carried out using direct current electrodeposition (DCED) method and pulsed electrodeposition (PED) method. Significant reduction in crystallite size has been observed with the increase in saccharin concentration (~10 g/L) irrespective of the electrodeposition method. In PED, it has been observed that an increase in pulse width causes a drastic reduction in crystallite dimension (~15 nm) of the deposited Ni-film. Further PED process yielded needle-shaped Ni grains under controlled process conditions unlike in DCED, where spherical grain structure was observed in the micrographs. However, these needle-shaped grains change their microstructure on addition of saccharin to the bath. A phenomenological model is presented to explain the observed microstructural changes.     

The effect of saccharin addition on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposit on Al

In a previous study, the effects of additive saccharin on internal stress, diffusion, and crystallization behaviors of electroless Ni–Cu–P deposits on Al were examined. In this study, tensile test results and microhardness measurements were used to investigate the effect of additive saccharin on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposits on Al. An increase in the saccharin content of the plating solution from 0 to 12 g/L results in nodule growth and void elimination in the deposits. The denser nodules in the deposit also cause a decrease in the tensile stress and reveal the effect of ΔTCE on compressive stress generation. Consequently, the mechanical properties of Ni–Cu–P/Al deposits in terms of microhardness, yield strength, modulus of elasticity, and ultimate tensile strength were improved. The fracture behavior of the deposit changes from transnodular to internodular when the saccharin addition is above 4 g/L.     

稀土铅基板栅材料的性能研究

研究了低钙高锡铅舍全添加稀土对合金力学性能和电化学性能的综合影响。测试并分析了该合金的强度、塑性、硬度、恒流腐蚀及析气等特性。研究结果表明,新型铅合金具有良好的力学性能和耐腐蚀性能,稀土的加入不但提高了合金的强度还能增加合金的塑性,同时提高了合金的耐腐蚀性能。     

The influence of the electroplating parameters on the conditions of deposited nickel‐iron coatings

Several specific electroplating parameters are varied to develop a manufacturing process for nickel‐iron coatings with low residual stresses and favourable structures and hardness values. Here, the produced coating conditions on the surface are characterised according to alloy compositions, microstructures, residual stresses, texture and microhardness as well as the elastic indentation modulus. The manufacture of the coatings was carried out in a laboratory electroplating plant. The process parameters are: electroplating in electrolytic baths with and without saccharin as an additive, with different iron content as well as with various current parameters. The results show significant influences of saccharin, as a bath additive, and of the pulse frequency during the reverse current pulse procedure on the coating conditions. Supplementary investigations are scheduled for determining the distributions of the conditions through the coating thickness. Similarly, micromechanical tests are planned. Process parameters with optimal conditions can then be selected from the determined process‐condition property relation. This is to subsequently serve as the basis for improving the manufacture of micro gear‐wheels. The micro gear‐wheels are produced by electroforming using the direct LIGA process.     

Low-stress permalloy for magnetic MEMS switches

The residual stress in the electroplated magnetic films is an important factor that limits the functionality of many micromagnetic devices. We have investigated the stress in electroplated Ni-Fe alloy for MEMS as a function of bath concentration, utilizing the wafer-bending method. Our investigation demonstrated that a low-concentration plating solution decreases the residual stress in the electrodeposits, and the stress is further decreased by increasing the saccharin additive content. We obtained the low-stress Permalloy Ni/sub 81/Fe/sub 19/ in our experimental conditions. We fabricated a bistable electromagnetic RF MEMS switch with deformation-free cantilever beam using the electroplated Permalloy.     

Ni/ZrO2梯度镀层的制备和性能

采用Watt型镀镍溶液，恒电流电沉积方法制备Ni／ZrO2梯度镀层．扫描电镜(SEM)测试和X-射线衍射分析表明，沿镀层的生长方向，ZrO2的含量由0逐渐增加到21％(体积分数，下同)，呈梯度分布；Ni和ZrO2各自在特定的角度分别出现其衍射特征峰，互不干扰，镀层中ZrO2的含量增高，衍射强度变强．断口分析表明，在梯度镀层的内部，材料的塑性变形能力大，韧性最好；沿镀层生长的方向，断口中的韧窝特征逐渐减小，镀层的韧性下降；在表层的断口中ZrO2微粒明显增多，呈团聚状态，基本上没有韧窝特征，镀层的韧性最差．Ni／ZrO2梯度镀层的韧性由外至内逐渐增加，呈梯度分布，其延展性为复合镀层的2．5倍．     

Effect of Electroplating Parameters on Microstructure of Nanocrystalline Nickel Coatings

In order to achieve the optimum conditions for electroplating nanocrystalline nickel coating from Watts-type bath, the effect of some process parameters namely, bath temperature, current density, and saccharin addition on grain size and texture coefficient (TC= I(200)/I(111)) of the deposits were investigated by X-ray diffraction (XRD). The results showed that in a bath containing 5 g/L saccharin, by increasing the bath temperature from 45°C to 55°C, the grain size decreased, whereas further increase of bat...     

聚苯乙烯塑料表面化学镀铜的研究

研究了聚苯乙烯表面化学镀铜的表面预处理以及化学镀铜工艺对化学镀铜的影响。结果表明,聚苯乙烯经过硫酸和重铬酸钾处理后．表面的极性官能团如羰基、羧基等大大增加。表面处理提高了塑料表面对金属镀层的附着力。对工艺因素的研究表明．化学镀铜的速度与温度、反应时间以及还原剂浓度等相关。     

Effect of a new condensation product on electrodeposition of zinc from a non-cyanide bath

Zinc electrodeposition from sulphate chloride bath was carried out in presence of condensation product formed between chitosan and veratraldehyde. The bath constitutents and operating parameters such as pH, temperature and current density were optimized through Hull cell experiments. Current efficiency and throwing power were measured. Polarization study revealed high shift of potential towards negative direction in the presence of addition agents. Corrosion resistance test revealed good protection of base metal by zinc coating obtained from developed electrolyte. SEM photomicrographs showed fine-grained deposit in the presence of condensation product. The IR spectrum of the deposit showed inclusion of the condensation product during electroplating. The consumption of brightener in the lab scale was 5 mLL⁻¹ for 1000 amp-h.