稀土添加剂对镍铁合金镀层的影响

通过赫尔槽实验和镀液的微分电容曲线，阴极极化曲线，分析稀土添加剂对Ｎｉ－Ｆｅ合金镀层的影响。结果表明，在Ｎｉ－Ｆｅ合金镀液中加入稀土添加剂可增大镀层光亮区的范围。这对获得光亮、致密的Ｎｉ－Ｆｅ合金镀层有较大意义。     

电沉积Ni-Fe-P非晶态合金镀层变温晶化的研究

用差热分析的方法研究了电沉积Ｎｉ－Ｆｅ－Ｐ非晶态合金镀层的变温晶化过程。通过实验得出不同铁含量的Ｎｉ－Ｆｅ－Ｐ合金在不同加热速度下的开始晶化温度、结束晶化温度,并计算出其晶化激活能。对不同Ｆｅ含量镀层的晶化激活能进行比较发现,Ｆｅ元素在Ｎｉ－Ｆｅ－Ｐ合金镀层中具有稳定非晶态组织的作用。     

电沉积Ni—Fe—P非晶态合金镀层高温晶化的研究

用差热分析的方法研究了电沉积Ｎｉ－Ｆｅ－Ｐ非晶合金镀层的变温晶化过程。通过实验得出不同铁含量的Ｎｉ－Ｆｅ－Ｐ合金在不同加热速度下的开始晶化温度、结束晶经温度并计算出共晶化激活能。对不同Ｆｅ含量镀层的晶化激活能进行比较发现，Ｆｅ元素在Ｎｉ－Ｆｅ－Ｐ合金镀层具有稳定非晶态组织的作用。     

电沉积Ni—Fe—P非晶态合金耐蚀性的研究

用电沉积法获得的Ｎｉ－Ｆｅ－Ｐ非晶态合金层的耐蚀性在某些介质中优于Ｎｉ及Ｎｉ－Ｆｅ合金；在碱性及强氧化性介质中，其耐蚀性相当或优于Ｎｉ－Ｐ合金；在含有Ｃｌ＾－的介质中，该合金未能阻止点蚀的产生。     

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。     

一种高耐蚀性的新型非晶合金镀层

试验了电沉积的Ｎｉ－Ｐ、Ｎｉ－Ｗ、Ｎｉ－Ｗ－Ｐ和Ｆｅ－Ｗ合金的腐蚀性能，并对添加元素Ｗ和Ｐ对非晶态镀层的耐蚀性的影响进行了研究，对合金的腐蚀速率与不锈钢的腐蚀速率进行了比较。结果表明，电沉积的Ｎｉ－Ｗ－Ｐ非晶态合金中的Ｗ含量高达５５．２％（重量）。合金硬度（ＨＶ）为７００到８００，在５５０℃热处理后达到１３００到１４００ＨＶ。硬度、耐磨性和耐蚀性均优于Ｎｉ－Ｐ非晶态镀层。腐蚀电位（Ｅｃｏｒｒ）因镀     

Ni~（2＋）、Fe~（2＋）和H_2PO_2~－、H_2PO_3~－在悬汞电极上的电化学行为

采用循环伏安法研究了Ｎｉ２＋、Ｆｅ２＋、Ｈ２ＰＯ２－Ｈ２ＰＯ３－在悬汞电极上的电化学行为以及Ｈ２ＰＯ２－、Ｈ２ＰＯ３－在ＫＣＬ支持电解质中的还原机理，对电沉积Ｎｉ—Ｆｅ—Ｐ非晶态合金中磷的沉积机理有进一步的认识。     

铜电极上Zn－Ni－P合金电沉积行为的研究

采用循环伏安法研究了铜电极上Ｚｎ－Ｎｉ－Ｐ合金电沉积行为。结果表明：在Ｚｎ－Ｎｉ合金锭液中加入ＮａＨ２ＰＯ２，Ｚｎ－Ｎｉ－Ｐ电沉积的阴极极化减小，对合金电沉积起活化作用，有利于Ｚｎ－Ｎｉ－Ｐ合金镀层的形成。所获得的Ｚｎ－Ｎｉ－Ｐ合金层与Ｚｎ层、Ｚｎ－Ｎｉ合金层相比阳极溶解峰电位正移，使含磷的锌基合金的耐蚀性大大提高。     

Ni^2＋,Fe^2＋和H2PO2^—,H2PO3^—在悬汞电极上的电化学行为

采用循环伏安法研究了Ｎｉ＾２＋、Ｆｅ＾２＋、Ｈ２ＰＯ２＾－、Ｈ２ＰＯ３－在悬汞电极上的电化学行为以及Ｈ２ＰＯ２＾－、Ｈ２ＰＯ３＾－在ＫＣＬ支持电解质中的不原机理，对电沉积Ｎｉ－Ｆｅ－Ｐ非晶态合金中磷的沉积机理有进一步的认识。     

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.     

镍镉合金扩散层内应力的研究

为了满足飞机发动机叶轮耐高温腐蚀性要求,研究了镍镉合金扩散层的结构,采取了两种方法来克服镍镉合金扩散层的弊病.选取合适的镀镍液或化学镀镍液制取低应力镍层;基体用液体喷丸方法提高零件表面强度及抗应力腐蚀能力.同时分析了电镀工艺参数对镍镉扩散层的影响.     

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 of silver–antimony alloys electrodeposited from ferrocyanide–thiocyanate electrolytes

The influence of electrolysis conditions on the internal stress, microhardness, electrical contact resistance, wear resistance, roughness, and friction properties of silver–antimony alloys deposited from ferrocyanide–thiocyanate electrolytes is studied. The internal stress of the coatings depends strongly on their antimony content. Stress changes and transition from compressive to tensile stress at increased antimony content in the alloy are observed. By internal stress measurements, conclusions can be drawn concerning the homogeneity or heterogeneity of the coating, that is, whether the coating consists of one or two phases. The changes in microhardness are related to variations of the internal stress and to the phase transition. The codeposition of antimony leads to a reduction of the coating roughness. Increased Sb content of the alloy leads to an increase in the electrical contact resistance and to reduction of the contact forces and wear resistance of the coatings. At large deviations from equilibrium, an oscillating electrochemical reaction is observed leading to space-time structures on the electrode surface.     

钛合金新型镀镍工艺的研究

通过在瓦特镀镍液中添加金属配位剂和金属阳极活化剂,对钛电极先采用阳极脉冲电流活化,再对活化后的钛电极进行脉冲电沉积,在TC11钛合金表面获得了结合力优良的镍镀层.研究了电解液组分、工艺参数对镀层结合力的影响.结果表明,在硫酸镍电解液中添加40 g/L阳极活化剂,采用1.4 A/dm2阳极脉冲电流对TC11钛合金进行电化学处理,可使TC11钛合金产生活性溶解,将脉冲电流切换为阴极电沉积后,便可在TC11钛合金表面沉积一层结合力优良的镍镀层.文章讨论了脉冲阴、阳极平均电流密度、占空比、频率、电解液组分等工艺参数对镍镀层质量的影响.     

Plasma electrolytic fluorination on Al alloys: Coating growth and plasma discharge behavior

The plasma electrolytic fluorination (PEF) process was conducted on 6061 Al alloy in the NH4F-EG non-aqueous electrolyte at room temperature. The microstructure and composition of the resultant coating were characterized by SEM, EDS, XRD and XPS. Also the coating growth and plasma discharge behavior were investigated by means of a well-designed jig, digital camera and OES, in order to understand the process characteristics. Results showed that the coating was dominantly composed of AlF₃, and characterized by a flake-like microstructure accompanying with some micro-pores and numerous micro-cracks. The internal of the coating was porous with a compact barrier layer near the substrate/coating interface. The fluorination of the substrate contributed the inward growth of the coating. PEF discharge sparks were characterized by tiny size and weak intensity during the whole process, of which the plasma electron temperature was about (3510 ± 110) K. Also, the discharge behavior and coating growth mechanism of the PEF process on Al alloy were discussed.     

柠檬酸根对镍钛合金表面电沉积羟基磷灰石涂层的影响

在含有0.042 mol/L Ca2+、0.025 mol/L H,PO-4及2.5×10-4mol/L柠檬酸根的电解液中进行阴极电沉积,成功地在NiTi合金表面制备了羟基磷灰石(HA)涂层.在电沉积之前,用5 mol/LNaOH对NiTi合金进行碱热预处理,可在其表面形成一层纳米针状氧化物.与不加柠檬酸根的电解液相比...     

Properties of silver-indium alloys electrodeposited from cyanide electrolytes

In this study an attempt was made to determine some structural and physicochemical characteristics of electrodeposited Ag-In coatings. Heterogeneous compact coatings with an indium content of up to 50 wt.% can be deposited from the cyanide electrolytes. The indium coatings have negative internal stress. The alloy coatings have small positive internal stress similar to the silver coatings, deposited from the alloy electrolyte in the absence of indium. The increase of the indium content in the alloy coatings leads to a decrease in their microhardness and abrasion resistance, to an increase in their roughness, and significantly improves their antifriction properties.     

超声波对硫酸盐镀镍及镀层性能的影响研究

研究了硫酸盐镀镍过程中施加超声波对阴极极化能力、阴极电流效率、分散能力、电化学反应阻抗、镀层内应力和硬度的影响。结果表明,镀镍过程中施加超声波能够降低阴极极化、提高阴极电流效率、改善电解液的分散能力、减小镍沉积阻抗;还能细化镀层晶粒、降低镀层内应力、提高镀层的硬度。     

铝-锰合金镀层的微弧氧化研究

在钢铁基体上采用熔盐电镀的方法获得铝-锰合金镀层,对镀层进行微弧氧化后制得铝-锰陶瓷膜。研究了不同质量浓度的硅酸钠电解液对铝-锰陶瓷膜厚度和硬度的影响;测定了相应质量浓度下的塔菲尔极化曲线,以此评价铝-锰陶瓷膜的耐蚀性;通过扫描电镜观察铝-锰陶瓷膜的微观形貌。