Influence of tartaric acid on zinc electrodeposition from sulphate bath

The effect of tartaric acid on zinc electrodeposition from sulphate plating bath was investigated by electrochemical impedance spectroscopy (EIS), stationary polarization curves, X-ray diffraction and SEM imagery. The study shows that it is possible to obtain homogeneous, compact and dendrites-free zinc deposits from sulphate solutions containing tartaric acid. For various hydrodynamic methods (rotating disc electrode and static vertical or horizontal electrode), the results indicate that, the presence of only small quantity of tartaric acid, may induce significant changes on deposition rates and deposit quality.     

摩擦电刷镀Ni-W-D合金镀液改良及镀层性能研究

给出了改良的Ni—W—D合金镀液配方,并介绍了镀液性能参数。采用自制的摩擦电刷镀装置进行了工艺实验。测定了镀层性能并采用X-射线衍射仪测试了镀层的相组成。分别用扫描电镜和能谱仪对镀层形貌及组成进行了观察与分析。结果表明：改良后的镀液得到的镀层有良好的结合力、较高的硬度和耐磨性,硬度平均值在620HV以上;且该镀层为单相镍面心立方固溶体,表面和横截面无明显裂纹,其中Ni,W．Co,Fe含量分别为84．05％,4．39％,7．66％,3．89％。     

光度法快速测定钯-钴镀液中的钯

以碘化钾为显色剂，采用分光光度法测定钯钻镀液中的钯含量。介绍了该方法的原理及分析步骤。探讨了测量波长、酸度、碘化钾浓度、抗坏血酸、发色温度等因素对测量结果的影响。在410nm波长下，钯浓度在8—80μ/10mL范围内测得吸光度与钯浓度之间的关系遵守比耳定律。另外，探讨了干扰元素的影响及其消除。加标回收试验结果表明，该方法准确度高，回收率大101．6％。     

变形锌合金在柠檬酸盐镀镍液中的腐蚀行为

利用动电位极化曲线和电化学阻抗谱研究了变形锌合金在柠檬酸盐电镀镍溶液中的腐蚀行为,通过场发射扫描电镜(SEM–EDS)表征了腐蚀表面形貌和成分。结果表明,锌合金在镀液中呈活性溶解状态,柠檬酸钠对锌合金有缓蚀作用;提高镀液温度不仅加剧锌合金腐蚀,还会加快镍置换反应发生。     

碱性锌酸盐体系锌-铁合金电镀添加剂的研究

锌基合金电镀层由于具有优良的耐蚀性而受到人们的关注。研制出一种用于碱性锌酸盐体系锌－铁合金电镀的添加剂ZFA，ZFA由一种主光剂DE、三种辅光剂如芳香醛、乙二胺四乙酸和苯甲酸钠以及一种润滑剂十二烷基磺酸钠组成。研究了ZFA中各组分对合金镀层外观的影响，优选出最佳ZFA配方。通过赫尔槽试验和扫描电子显微技术研究了ZFA的加入对合金电镀光亮电流密度范围和支表面、断面形貌的影响。结果表明，ZFA的加入能扩大合金电镀的光亮电流密度范围，所得合金支平滑、光亮、均匀、致密，与基体结合力好。     

Physico-chemical properties of Zn-Fe alloy deposits from an alkaline sulphate bath containing triethanolamine

The composition, properties, structure and morphology of Zn-Fe alloy deposits obtained from an alkaline sulphate bath have been investigated. The bath containing triethanolamine produced smooth, uniform and bright Zn-Fe alloy deposits having the desired 15–25% Fe. The deposition potentials of Zn-Fe alloy lie between the potentials of the individual metals. Increased current density lowered the Fe percentage in the alloy deposit. The structure and morphology of the alloy deposits were found to depend on the Fe percentage in the alloy.     

碱性锌-钴合金镀液中锌、钴含量的测定

为获得耐蚀性良好的锌 钴合金镀层 ,必须维持镀液中的锌 钴含量在工艺范围内。采用EDTA滴定和分光光度相结合的方法测定碱性锌 钴合金镀液中的锌、钴含量。介绍了该方法的分析步骤 ,探讨了测量波长的确定 ,亚硝酸钠、镀液共存组分、酸度以及铜离子和铁离子等杂质对测量结果的影响。结果表明 ,在 530nm波长下 ,钴浓度在 0 - 3μg/mL范围内所测吸光度与钴浓度间的关系遵守比耳定律 ,该方法准确度高 ,回收率达 97% - 1 0 3 5%。     

Electrodeposition of copper into trenches from a citrate plating bath

The electrodeposition of copper from a citrate solution has been investigated as a function of pH of the plating bath, and applied to the filling of 500 nm trenches. Speciation diagrams of copper in aqueous citrate solution were used to select four deposition baths with different dominant copper-citrate complexes, which was corroborated using UV–vis spectrophotometry. The electrochemical properties of the plating baths were determined in order to relate the deposition kinetics to the morphology of deposits in trenches. SEM images illustrate that the plating bath at pH 3.1, where only mild inhibition of the deposition kinetics is observed, is capable of adequately filling the trenches.     

Fe-W-P-Ce合金复合刷镀液组分含量影响的分析

以FeC l2为主盐,在碳素钢上制备了Fe-W-P-Ce复合刷镀层。讨论了主盐类型及含量,辅盐、稀土元素、缓冲剂、亚磷酸以及络合剂含量对镀层组成及沉积速度的影响。结果表明,以上各组分含量对镀层质量及沉积速度均有显著影响:主盐FeC l2型优于FeSO4型,镀液中W6 与Fe2 质量分数比值在20%~30%时,镀层中钨含量增加较快;当四硼酸钠含量为10 g/L时沉积速度达最大;当镀液中H3PO3含量为50 g/L时,镀层中磷、铁及钨的质量分数分别为8%、48%、32%,镀层为非晶态。     

镀镍液中铁杂质的影响及处理方法

分析了镀镍液中铁杂质的产生途径及其对镀镍层质量的影响。介绍了不同情况下铁杂质的处理方法:ρ(Fe2 )<200mg/L时,可采用添加WZ-Fe除铁剂的方法处理;日常维护,可以采用小电流电解方法除去铁杂质;当Fe2 的质量浓度很高时,用KMnO4或H2O2氧化法进行处理。     

玻璃纤维化学镀镍钴磷合金废液的处理与回用

采用化学沉淀的方法对玻璃纤维化学镀镍钴磷废液进行了再生。以乙酸钙为沉淀剂,考察了在不同的温度、用量、pH值以及反应时间条件下,去除亚磷酸根的情况,讨论了采用Ca(OH)2、CaO为沉淀剂的除磷效果;以乙酸钙处理后的废液对玻纤施镀,用扫描电镜和能谱分析对镀层进行了分析,得知施镀效果较好,从亚磷酸根的去除效率以及施镀效果综合考虑,得出用乙酸钙处理废液时的最佳条件为:反应温度40￣50℃,反应时间20min,乙酸钙的投加量为90￣100g/L。     

焦磷酸盐镀铜液中正磷酸盐含量对镀层性能的影响

介绍了一种焦磷酸盐镀铜溶液中铜、总焦磷酸根、磷酸根、柠檬酸铵含量的分析方法和计算方法。分析了正磷酸根产生的原因及其危害,并给出了一种化学处理方法。对正磷酸根含量不同的镀液进行了分析,并测试了相应镀层的性能?采取了不同的措施对镀液进行改进,并对效果进行了讨论。结果表明,正磷酸根的存在是不可避免的,控制槽液温度和pH值、定期过滤溶液、补充新料等措施都可抑制正磷酸根含量的增长。     

羧基配位剂对电镀镍–磷合金的影响

以羧基类物质作配位剂,在A3钢板表面电沉积制备Ni–P合金镀层。镀液基础组成和工艺参数为:NiSO4·6H2O 240 g/L,NiCl2·6H2O 45 g/L,NaH2PO2·H2O 50 g/L,H3BO3 35 g/L,NaF30 g/L,pH 2.0,温度70°C,电流密度2.5 A/dm2,时间20 min。研究了镀液中羧基配位剂含量对Ni–P镀层沉积速率和耐蚀性的影响。结果表明,随羧基配位剂含量增大,沉积速率减小,镀层耐蚀性先改善后变差。其适宜含量为20~30 g/L。羧基配位剂含量为25 g/L时,镀层外观光亮、结合力良好,耐蚀性和耐磨性优于未加配位剂的镀层。镀层的P含量为18.11%,属于高磷非晶态Ni–P镀层。羧基配位剂具有细化镀层晶粒的作用,使镀层表面更为平整、致密。     

硫酸盐-柠檬酸盐体系锌锰合金电镀液稳定性的研究

锌锰合金镀液存在电流效率低,镀液稳定性差等缺点,选择硫酸盐－柠檬酸盐体系锌锰合金镀液,研究了阳极,二价锰离子以及连续作用等因素对镀液稳定性的影响,结果表明：采用不锈钢阳极和阴离子膜可提高镀液稳定性,防止二价被氧化,加入氢氧化可消除因补充锌锰离子而积累的硫酸根离子。     

电镀液中柠檬酸钠的测定

提出了一种测定电镀液中柠檬酸根含量的新方法。利用DowexlX8-200强碱型阴离子交换树脂分离纯化电镀液中的柠檬酸根,在无水乙醇和三氟化硼-乙醚介质中酯化后,以苯甲醛做内标,直接用气相色谱-二级质谱(GC／MS／MS)进行分析测定。所用色谱柱为DB-1型弹性石英毛细管柱。试验结果表明,该法抗干扰能力强,选择性高。样品测定的精密度为3．70％,回收率为97．53％。将此法用于电镀液中柠檬酸钠的测定,得到了满意的结果。     

Electrodeposition of zinc-cobalt alloy from a complexing alkaline glycinate bath

The influence of cobalt on the electrodeposition of zinc onto AISI 1018 steel was studied in weakly alkaline glycine solutions. Thermodynamic calculations were performed to construct predominance-zone diagrams to identify the stability of the zinc and cobalt glycine complexes, and experimental studies of electrochemical behavior and deposit properties were conducted. When zinc is present, cobalt deposition shifts to more negative potentials, producing ZnCo alloys. Two main reduction steps were observed for electrodeposition from the ZnCo bath: the first at low potentials was due to ZnCo electrodeposition. In the second, at more negative potentials, cobalt content in the deposit increased forming a range of intermediate phases, and the hydrogen-evolution reaction became significant. The presence of Co(II) in the bath modified the morphology of the deposits as well as reducing the faradaic metal-deposition efficiency. ZnCo-deposit morphology was modified by the applied current density as well as the metal composition of the coating. X-ray diffraction studies revealed that cobalt oxide or hydroxide is formed during ZnCo electrodeposition, indicating that an elevation of the interfacial pH plays a role in the alloy deposition process.     

钢铁基体上HEDP体系无氰滚镀铜工艺

探讨了HEDP(羟基乙叉二膦酸)溶液体系滚镀铜工艺的可行性。通过正交试验和单因素实验研究了配位剂含量、主盐含量、电流、温度、装载量和施镀时间对滚镀铜的影响,得到最佳配方和工艺条件为:HEDP 120 g/L,Cu SO4·5H2O 16 g/L,K2CO3 60 g/L,p H 9.5,温度50°C,阴极电流2.0 A,滚筒转速15 r/min,装载量50 g/筒。在该条件下滚镀1 h,可获得高、低电流密度区平均厚度分别为7.39μm和1.60μm,与钢铁基体结合良好的半光亮铜镀层。该滚镀铜工艺基本满足预镀铜的要求,但对有光亮度要求的产品,需要往镀液中加入适量添加剂HEAS。     

稀土对化学镀Ni-W-P镀液及镀层性能的影响

研究了4种稀土元素Nd、Pr、Ce、La的硫酸盐及其氧化物对化学镀Ni—W—P镀液的沉积速度和镀层耐硝酸滴定变色时间的影响。结果表明,4种稀土的硫酸盐均降低了镀液的沉积速度,并使镀层的耐蚀性能下降;Nd、Ce、La的氧化物亦使镀层的耐蚀性下降,而当ρ(Pr2O3)为4mg／L时,镀液的稳定性为未加Pr2O3时的2倍,其沉积速度明显加快,镀层的耐硝酸滴定变色时间超过2000s,硬度明显增大,SEM图表明该镀层呈现致密而均匀的胞状形貌,表面质量优于未加稀土的镀层,X-射线衍射图也表明Pr2O3促进了镀层的非晶态化程度．从而提高其耐蚀性能。     

柠檬酸盐体系低温化学镀镍的研究

提出一种柠檬酸三铵体系的低温化学镀镍工艺。研究了该镀液的温度、pH及镀液组成对沉积速度的影响。得出适宜的工艺条件为:40g/L硫酸镍、35g/L次亚磷酸钠、30g/L柠檬酸三铵,pH9~9.5,θ为45℃。经扫描电子显微镜观察,镀层表面均匀平整;经X-射线衍射分析,镀层具有晶态结构。该工艺稳定,沉积速度可达4.5mg/(cm2·h)。     

Zinc-nickel alloy electrodeposition from uncomplexed acid bath

Zinc-nickel alloys, as protective coatings, are well known and a new citrate bath has been investigated. It was observed that boric acid favoured nickel deposition playing the dual role of specific adsorption and catalysis. The voltammetric behaviour of the alloy deposition in the presence of boric acid is described. The effect of Ni/Zn ratio, and potential scan range on the cathodic and anodic portions of the voltammograms are discussed. The presence of two cathodic peaks at high Ni/Zn ratios, which disappeared at lower ratios was identified.