镀液中镍锌含量比对酸性液电镀Zn-Ni合金的影响

为了确定镀液中镍锌含量比对酸性液电镀Zn-Ni合金质量的影响.利用能谱仪、扫描电镜以及耐腐蚀实验等方法分析镀层的形貌和性能.结果表明:在镍锌含量比为0.75时镀层中镍含量为13%.效果较好:当镍锌含量比较低时很难施镀,得到的镀层形貌不好,在高于0.75时效果也不理想,在镍锌含量比为0.75时效果最好,镀层致密,颗粒细小均匀并且不易脱落;镀层有良好的耐腐蚀作用.     

连续电镀锌-镍合金技术的研究

提出了连续电镀锌镍合金的高氯化氨-弱酸型镀液工艺参数,对镀液成分、pH值、温度、阴极电流密度对镀层镍含量的影响及连续电镀锌镍合金的镀速控制等问题进行了研究.得到外观良好、镍含量在13%～15%的锌镍合金镀层.     

锌镍合金电镀技术的研究

研究了采用锌镍合金为阳极进行电镀时,工艺条件对锌镍合金镀层镍含量的影响,寻找出耐蚀性是镀锌层５倍以上Ｚｎ－Ｎｉ（１３％）合金镀层电镀的工艺条件。对镀液进行了连续电镀试验,电镀后镀液中金属离子浓度波动小,采用合金阳极进行电镀可以基本维持金属离子浓度的稳定,还应用多种测试方法,检测了镀层的结合力。     

正交试验优化电镀Zn-Ni-P合金工艺

选取影响电镀Zn-Ni-P合金的6个工艺参数，设计了125(56)正交试验方案，探讨了镀液组成和电镀制度对Zn-Ni—P合金镀层性能的影响，用极差法分析了各工艺参数对镀层性能影响的显著性并确定了最佳工艺条件。优化验证实验结果表明：该工艺稳定，得到光亮、致密、外观平整的Zn-Ni—P合金镀层，得到的锌镍磷合金镀层的耐蚀性优于锌镍合金，且其耐蚀性随镀层中磷含量的增大而提高。     

汽车轮毂用铝合金表面镍镀层的耐蚀性能研究

在汽车轮毂用的铝合金表面上电镀镍。研究镀液pH值、电流密度、镀液温度等因素对镀层耐蚀性能的影响。用线性扫描伏安法研究镍镀层在3.50%NaCl溶液中的耐蚀性能,用SEM和XRD表征了镍镀层的形貌和结构。结果表明,电镀的最佳工艺条件为:镀液pH为4.2,电流密度为30mA/cm2,镀液温度为58℃;在该条件下获得的镍镀层有很好的耐蚀性能,其结构为立方晶系。     

电镀金刚石钻头胎体性能与电镀工艺的关系研究

电镀金刚石钻头的胎体性能对岩石的适应性显著影响钻头的钻进效果。为了确定电镀金刚石钻头胎体材料性能与镀液组成及电镀参数的关系,本文从研究镀液配方和优化工艺参数入手,采用正交试验方法研究了镀液中镍离子浓度、钴离子浓度、镀液pH值和阴极电流密度等四个因素对镀层耐磨性的影响。镀层耐磨性以硬度和孔隙率加权综合表示。采用极差分析法处理了试验结果,得出了影响镀层耐磨性的主次因素为(从主到次)镀液pH值→阴极电流密度→钴离子浓度→镍离子浓度,从而确定了可获得不同耐磨性镀层、适应不同地层的镀液配方和电镀工艺参数。研究为有针对性地制造和选用电镀金刚石钻头提供了较好的依据。     

光亮氯化物电镀锌铁合金工艺研究

采用霍尔槽试验成功了一种光亮氯化物电镀低铁含量的锌铁合金工艺,探讨了光亮剂、主盐、导电盐、稳定剂、工艺条件的影响,检测了镀液、镀层性能。结果表明：本工艺所得镀层光亮如镜,白钝酷似镍层,主要性能指标优于纯锌镀层,适用于钢铁零部件的高耐蚀性电镀。     

光亮碱性Zn-Al合金电镀工艺研究

在碱性锌酸盐镀锌液中加入铝盐，研究成功了一种光亮碱性锌铝合金电镀工艺。采用霍尔槽试验探讨了镀液成分和工艺条件对镀层质量的影响，检测了镀液和镀层性能。研究结果表明：镀液阴极电流效率达到80%以上，镀液分散能力和复盖能力好，镀层中铝含量为1．5％左右，所形成的Zn-Al合金镀层结晶细致、光亮度好、结合力好、耐蚀性优良，适用于作高耐蚀性镀层。     

Au-Cu-Ni 合金在铜基材表面的无氰电镀

采用亚硫酸盐体系在铜基材表面进行Au-Cu-Ni合金的电镀,研究了镀液中铜、镍浓度与镀层成分的关系。结果表明,镀液中铜、镍浓度较高时,Au-Cu-Ni合金镀层中的铜、镍含量也会增加。用金、铜和镍浓度分别为20、0.7和3.5 g/L的镀液电镀得到的Au-10.35Cu-2.50Ni合金镀层显微硬度(HV0.025)达到297,电阻率1.84,镀层光亮致密,耐腐蚀性好。镀层磨损量小,接触电阻变化值小且稳定,可满足高导电要求的滑动电连接器件的要求。     

硫酸盐体系电沉积镍钨合金工艺研究

目的探究硫酸盐体系镀液中柠檬酸浓度、钨酸钠浓度及镀层热处理工艺,对镍钨合金镀层中钨含量、镀层硬度、镀层微观形貌和物相组成的影响。方法采用合金电沉积方法,以低碳钢为基体,在不同成分的镀液中制备了一定厚度的镍钨合金镀层,然后用不同的热处理工艺进行后处理。用扫描电镜(SEM)及其自带的EDS能谱观察镀层的微观形貌,检测镀层的钨含量。使用X射线衍射(XRD)分析镀层的物相组成、晶粒大小和晶格畸变情况。使用显微硬度计对合金镀层的硬度进行了测试。结果随着镀液中钨酸钠浓度的增大或者柠檬酸浓度的减小,镀层中的钨含量提高,晶粒尺寸减小,维氏硬度增大。热处理氛围对镀层硬度的影响不大,但会改变镀层微观形貌,镀层硬度随热处理温度先增大后减小,也随保温时间先增大后减小。结论当镀液中含有钨酸钠45 g/L,柠檬酸45 g/L,电镀完成后将镀层在400℃氩气保护下热处理1.5 h,得到的镀层是以镍为溶剂、钨为溶质的置换型固溶体Ni_(17)W_3,其具有表面平整、无裂纹,硬度达894HV0.1的优良性能。     

Preparation and characterization of Cr-P coatings by electrodeposition from trivalent chromium electrolytes using malonic acid as complex

Cr-P coatings were prepared by electrodeposition from trivalent chromium plating bath using malonic acid as complex. The influences of bath composition on the trivalent chromium electrodeposition process and deposited coating properties were studied. The effects of plating parameters such as current density, bath pH and plating time on structure and morphology of deposited coatings were investigated in detail. XRD, SEM, EDAX and XPS techniques were used to characterize the Cr-P deposited coatings. Results show that the composition, microstructure and surface morphology of the Cr-P coatings depend on bath composition and plating conditions including bath pH, current density, plating time, etc. Results of EDAX and XPS indicate that the deposited coatings contain Cr(s), Cr(III), phosphorus, oxygen and carbon. The optimum bath composition was obtained using malonic acid as complex and the mechanism of Cr-P electrodeposition was analyzed. The optimum plating parameters for good-quality chromium deposited coating are pH 2-3, current density 3-12 dm², temperature 35 °C and Ti/IrO₂ as anode. These results may be of great practical and theoretical significance for further improvement of trivalent chromium plating process.     

Properties of fluoride film and its effect on electroless nickel deposition on magnesium alloys

The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.     

化学沉积Fe-Ni-La-P合金镀层影响因素分析

采用化学沉积的方法制备Fe-Ni-La-P合金镀层,通过重量法、电化学法分析了镀液成分对Fe-Ni-La-P镀层沉积行为的影响.结果表明,改变镀液组成和沉积工艺,沉积速度随之改变.用电化学方法计算得到的沉积速率与重量法测得的的沉积速率有相同的变化趋势.     

铜钼体系钢铁常温发黑液研究

通过单因素实验及正交实验研究并优化了一种铜钼体系无硒钢铁常温发黑液。讨论了pH值、温度及发黑液组成等对45号钢发黑膜质量的影响。用此配方及工艺在45号钢片上制得的发黑膜色泽好、结合力高、覆盖均匀并具有优良的耐蚀性能。     

Electrodeposition of Copper-Nickel Alloys from a Citrate Bath Containing Boric Acid

Copper-nickel alloys have been electrodeposited on steel substrates from a bath containing copper sulphate, nickel sulphate, sodium sulphate, sodium citrate and boric acid. Galvanostatic cathodic polarization, cathodic current efficiency and composition of the alloys were studied as influenced by bath composition, current density and temperature.

The bath is characterized by high cathodic current efficiency. Current density is found to strongly influence the composition of the deposits. At low current densities (lower than a certain transition current density), a copper-rich alloy is deposited with copper (the more noble metal) being the preferentially deposited metal. At larger current densities, nickel becomes the nobler metal and is deposited preferentially. The magnitude of the transition current density depends upon the bath composition and temperature. The structure and surface morphology of the as-deposited alloys were examined by XRD and SEM. The results reveal the presence of a single solid solution phase with face centred cubic structure. The morphology of the deposits is mainly controlled by the alloy composition.     

镀液锡泥对黑灰程度及镀层耐蚀性的影响

研究了实验室条件下镀液中锡泥的量对软熔后镀层表面黑灰的量以及镀层耐蚀性的影响,通过XPS等测试发现,锡泥的主要成分为二氧化锡,其相应镀层在高温软熔后产生的黑灰的主要成分也为二氧化锡,结果表明,随着镀液中锡泥量的增加,软熔后镀层表面的黑灰程度增加,通过对表征镀层耐蚀性的合金电偶电流值及酸洗时滞的测试发现,随着锡泥投入量的增加,镀层的耐蚀性下降,且两者之间有很好的对应关系。     

化学镀Ni—P—B合金的工艺

研究了以次亚磷酸钠和硼氢化钾为还原剂的化学镀 Ni-P-B 溶液。讨论了镀液组成和工艺对沉积速度的影响.提出获得良好 Ni-P-B 合金镀层的最佳镀液组成和操作条件。结果表明:Ni-P-B 镀层的耐磨性比 Ni-P-B 镀层均好。     

28CrMo钢的Ni-P合金镀工艺

研究了制备工艺对28CrMo钢Ni-P合金镀层性能的影响。结果表明,镀液成分中的氯化镍和稀土含量及电流密度和镀液温度都会影响镀层的厚度和硬度。本试验条件下的最佳制备工艺是镀液成分为含50 g/L的氯化镍+2 g/L的稀土(镀液中其他成分为硫酸镍180 g/L、磷酸45 g/L、亚磷酸10 g/L),电流密度为8 A/dm2,镀液温度为65℃。在此条件下得到的镀层为非晶态,镀层性能最好。     

QPQ技术的盐浴调整和维护

详细介绍了QPQ技术的盐浴调整和维护方法及铁素体氮碳共渗盐浴中氰酸根CNO-、氰根CN-和碳酸根CO3=的分析方法。在大生产中,保持盐浴成分的稳定和可控,使其在规定的范围内波动,是得到合格产品的必要条件。此外还论述了QPQ技术的氮碳共渗盐浴和氧化盐浴的成分控制和维护方法,包括新盐的熔化,老盐的调整、维护和保养。     

Bath chemistry and aluminum cell performance—Facts,fictions, and doubts

This article examines the relationship between bath chemistry and aluminum cell performance together with facts, fictions, and doubts arising from data available in the literature. An earlier trend toward more low-ratio baths now appears to have stopped at about 12% AIF₃, which is a typical bath composition used in modern, high-amperage cells. Widely different bath compositions are still used in older cells. Current controversies concern the effect of the alumina content in the bath on current efficiency and energy consumption, the true effect of LiF-containing modified baths, and the optimum content of AIF₃. Recent current efficiency data for lithium-modified low-ratio baths are discussed, together with the expected future development of bath chemistry in aluminum electrolysis cells. Further changes in bath composition can contribute to small, but significant improvements in cell performance, even in the best modern cells.