氯化物电镀Zn—P合金的研究

研究了Ｚｎ－Ｐ合金电镀液组成及工艺条件对镀层含磷量的影响，在最佳工艺参数条件下，可得到磷的质量分数为０．１％左右的Ｚｎ－Ｐ合金镀层。对镀液、镀层性能进行了测试，实验证明经银白色钝化后的Ｚｎ－Ｐ合金镀层的耐蚀性能是纯锌镀层的２倍以上。     

电沉积Zn—Ni合金的耐蚀性研究

在含锌的合金电镀中,已报道的有Zn—Ni,Zn-Sn,Zn-Fe,Zn-Co和Zn-Cd.其中以Zn-Ni和Zn-Fe合金电镀被认为最有发展前途.关于Zn-Ni合金镀层优异耐蚀性的认识源于这样一个实验:四十年代美国宾西法尼亚3S公司(Standerd Steel Spring)在钢铁上先镀一层4μm Ni,后镀一层同样厚度的锌,然后在370℃以下热扩散30到120分钟,得到具有4种晶相的Zn-Ni合金.其腐蚀试验表明,8μm的Zn-Ni合金经盐雾试验1536小时,表面只有2%区域出现腐蚀,同样厚度的Zn镀层,试验1000小时,有25%出现锈蚀.经大气腐蚀试验16个月,这种合金无任何腐蚀,而5μm厚的镍镀层大气试验1个月有25%出现锈蚀.但这种工艺并未获得推广,因为大多数电镀车间并不配备这样的加热炉.然而,Zn-Ni合金所具有的优异防腐蚀性能却大大的推动了人们直接从水溶液中获得Zn-Ni合金的研究.文献[3]介绍了已发表的各种配方与工艺,但其中最关键的光亮剂都以“添加剂”二个字给保密起来了.事实上没有光亮剂的Zn-Ni合金镀层是十分粗糙的,其防护能力不算高.Zn-Ni合金镀层在国内大规模的应用尚不多.在日本,1984年住友金属工业公司,有两条Zn-Ni合金电镀生产线,年产44.4万吨Zn-Ni合金钢板.     

电镀ZnFe—P合金的腐蚀行为

1 前言 为了满足较严酷的腐蚀环境对镀层的要求,近年来开发Zn-Ni,Zn-Fe等高耐蚀的合金电镀工艺。文献报道含磷的锌基合金如Zn-P,Zn-Ni-P等具有高耐蚀性与抗点蚀的特点。初步实验结果表明,这些合金的耐蚀性比同厚度的镀锌层高出几倍到十几倍。     

Zn-Ni合金镀层中添加第三种元素和纳米颗粒的研究新进展

介绍了在汽车、航空航天等行业中得到广泛应用的钢铁零件电镀Zn-Ni合金镀层,以及往碱性、氯化物等锌镍合金镀液中加入Fe、Co、Mn、Ce、P等第三种元素所获得的锌镍三元合金镀层,具有更优良的耐腐蚀性、催化性等性能的情况。介绍了往Zn-Ni合金镀液里加入氧化硅、氧化铈、氧化钛、氧化铝、碳化硅等纳米颗粒的进展情况,发现含有纳米颗粒的锌镍复合镀层具有耐腐蚀性、耐磨损性、热稳定性更好,硬度更高等优点。梳理了2016年以来在Zn-Ni合金电镀中添加第三种元素和纳米颗粒的多层镀层研究新进展。从Zn-Ni单一镀液中沉积Ni-P和Zn-Ni合金多层镀层时,在低电流密度下沉积出Ni-P层;在较高电流密度下,沉积出含3.2%P的Zn-Ni-P合金镀层,这种多层镀层可以大幅度提高钢铁零件的防腐蚀性能。介绍了在含12%Ni的Zn-Ni镀层上镀覆Ni-Co-SiC纳米复合镀层的情况,这种多层结构既可以提高镀层的结合力,又可提高其在3.5%NaCl溶液中的耐腐蚀性能。该复合镀层是一种硬度高、磨损量低的新型Zn-Ni合金复合镀层。     

装饰性Zn-Ni/Ni-P镀层的研究

为进一步提高镀层的耐蚀性、降低脆性,在含有缩合物添加剂的镀液中制备了结晶为14～33nm的Zn-Ni合金镀层.采用SEM、XRD对镀层的微观形貌及相组成进行了研究.将此Zn-Ni合金镀层作为底层,制备了双层Zn-Ni/Ni-P镀层,结果表明:双层镀层的耐蚀性比装饰铬组合镀层提高1倍以上,而且镀层的氢脆大大降低,尤其适合于高强度零件的电镀.     

Zn-Ni合金镀层耐蚀性的分析

通过硫酸盐-氯化镍体系的Zn-Ni合金镀液获得的光亮高耐蚀的镀层,经镀层的盐水浸泡实验及阳极极化曲线等的分析,说明Zn-Ni合金镀层的耐蚀性要优于锌镀层。     

铀及铀合金的防腐蚀电镀层研究进展

综述了铀及铀合金的蚀刻；总结了铀及铀合金的防腐蚀电镀层，包括Ni镀层、Ni Zn双重镀层、Zn-Ni合金镀层；介绍这些镀层的制备工艺；评述了这些电镀层对铀及铀合金的防腐蚀性能及保护机理。     

高强度航空结构钢电镀Zn-Ni合金的氢脆性能

目前,对航空300M超高强度结构钢电镀Zn-Ni合金的氢脆性能研究鲜见报道。采用正交试验法研究了工艺参数对300M钢Zn-Ni合金镀层含Ni量和氢脆性能的影响规律;采用EDA能谱分析、SEM形貌观察、缺口拉伸试验和断口分析等方法,对Zn-Ni合金镀层的氢脆性能和断口特征进行了分析研究,探讨了其代替松孔镀镉层的可行性。结果表明:从工程应用安全性出发的氯化物-硫酸盐体系Zn-Ni合金电镀优化工艺条件为镀液Ni2+/Zn2+质量浓度比0.53、温度30℃、电流密度4 A/dm2,所得镀层的氢脆敏感性低,符合航空工业高强度钢氢脆性能要求,可以代替剧毒镀镉工艺用于航空结构钢的表面防护处理。     

铜及其合金化学镀工艺研究

研究了铜及其铜合金化学镀Ｎｉ－Ｐ合金的工艺条件，对镀层的性能、成分，结构，耐蚀性和结合力进行了分析研究。研究时效处理条件对镀层结构、硬度、摩擦磨损性能的影响，研究结果表明：该工艺可得到结合力好，磷含量在１２％以上的非晶态合金镀层基表面硬度，耐磨性，耐蚀性都有显著的提高。     

镁合金表面制备高红外发射率和高导电率热控膜层

目的通过电沉积方法在镁锂合金表面制备具有高红外发射率以及高导电率的镀层,满足其在太空中散热以及电磁屏蔽的需要。方法通过前处理工艺(碱洗→酸洗→预钝化→化学镀镍磷→电镀铜)提高镁锂合金基体的耐蚀性能以及与后续镀层的结合力,并在此镁锂合金前处理工艺的条件下,电沉积多孔Zn-Ni合金镀层。通过热循环测试和电化学方法评价各镀层的电化学腐蚀行为和各镀层之间的结合力。结果各镀层之间的结合力良好,化学镀Ni-P层、电镀Cu层和多孔Zn-Ni层的耐蚀性能均优于镁锂合金基体,该组合镀层的协同作用可以有效地保护镁锂合金基体,提高其耐蚀性。结论最外层多孔Zn-Ni合金镀层主要由Ni2Zn11、NiO、NiS组成,其红外发射率为0.90,电阻率小于0.01 m?/cm。这表明多孔结构可以有效提高金属合金镀层的红外发射率,并保持合金镀层的高导电性。     

锌-铁合金仿银装饰电镀研究

在焦磷酸盐体系电镀锌－铁合金的基础上^[1],通过对稳定剂的种类、加入量以及工艺条件的探索试验,确定了最佳的电镀液配方和工艺条件。得到了更加光亮、致密和具有仿银效果的锌－铁合金装饰镀层。     

几种不同材料在含硫介质中的腐蚀性

用失重法和恒电位极化法研究了45#碳钢、1Cr18Ni9Ti、304不锈钢和Ni-P合金镀层在含S介质中的腐蚀性.结果表明,低温条件下,S2-浓度变化对4种材料阴极极化和阳极极化影响较小,1Cr18Ni9Ti和304不锈钢的极化曲线相似,为典型的阴、阳极控制的电化学腐蚀过程,自腐蚀电位和自腐蚀电流相近;Ni-P合金镀层出现了钝化区;45#碳钢出现了阳极控制的扩散过程.温度升高,腐蚀速率增大,1Cr18Ni9Ti和304不锈钢的极化率变大,Ni-P合金镀层的钝化性能减弱, 1Cr18Ni9Ti、304不锈钢和Ni-P合金镀层均是含S介质中的耐蚀材料.     

Zn－Fe合金电镀新技术在钢铁防护中的应用

钢铁基体防护技术实施的电镀、有电镀与热浸镀之分,同样都以金属镀为镀层,相互差距较大;热浸镀防怕锭远优于电镀锌,电我站成本则又远低于热浸镀锌。锌铁合金新技术,兼二者之宅又避其短。防护性能不次于热浸镀锌,比电镀锌提高了３－５倍。生产成本仅为热浸镀锌的１／１０,比电镀锌也偏低,且对环境无污染。对这方面的实例作了具体论述,匀 合很有发展前景的工艺。     

Zn-Fe-SiO2复合镀层的性能研究

分别采用硫酸盐体系和氯化物体系的最佳工艺条件电沉积制备了高铁(Fe mass%>1%)和低铁(Fe mass%<1%)的Zn-Fe-SiO2复合镀层,并系统测试了不同厚度Zn-Fe-SiO2复合镀层的耐蚀性、结合力、孔隙率和氢脆性等综合性能,同时与电镀Zn及Zn-Fe合金进行了对比.实验结果表明：Zn-Fe-SiO2复合镀层的耐蚀性及其它综合性能均优于Zn-Fe合金镀层和Zn镀层.因此,相对于电镀Zn及Zn-Fe合金,电沉积Zn-Fe-SiO2复合镀层技术具有先进性,应用前景良好.     

Electrodeposition and properties of Zn,Zn–Ni,Zn–Fe and Zn–Fe–Ni alloys from acidic chloride–sulphate electrolytes

Abstract

Zn, Zn–Ni, Zn–Fe and Zn–Fe–Ni films have been deposited by electrochemical deposition technique onto steel plate substrates. The objective of this study was to characterise the corrosion properties of these alloys in saline solution for the application as new environmentally friendly sacrificial coatings in the protection of steel structures. The morphological and structural properties of the alloys were systematically studied using XRD and SEM techniques. Cyclic voltammetry of the individual metals was performed to help understand the electroplating process of the films. Grain sizes of the films were calculated using Scherrer's formula. Partial substitution of Zn to Fe and Ni leads to an improvement in the corrosion resistance. Compared with other zinc alloys, the Zn–Ni alloy deposit was the noblest.     

新型耐高压铸造锡青铜的研制

以ZCuSn3Zn8Pb6Ni1合金为基础,通过添加Fe和Co,开发了耐高压铸造ZCuSn3Zn8Pb6Ni1FeCo合金,研究了Fe和Co对合金组织和性能的影响.结果表明,ZCuSn3Zn8Pb6Ni1FeCo合金显微组织与ZCuSn3Zn8Pb6Ni1的相同之处在于均以α-{ Cu,Sn,Zn }为基体,存在硬脆相δ- Cu10Sn3,Pb以单质形式析出;ZCuSn3Zn8Pb6Ni1FeCo合金中还存在α-Fe和γ-Fe析出相,以及CoCu2Sn 、Fe3Co7、Fe4Zn9等硬质相,这些硬质相和基体之间为共格或半共格关系;ZCuSn3Zn8Pb6Ni1合金铸造组织为典型的枝晶组织,晶粒平均直径约3 mm,抗拉强度为180～230 MPa,而ZCuSn3Zn8Pb6Ni1FeCo合金为等轴晶组织,晶粒平均直径为20～60 μm,抗拉强度为400～450 MPa,伸长率在20%以上;ZCuSn3Zn8Pb6Ni1FeCo合金消除了明显存在于ZCuSn3Zn8Pb6Ni1合金中的Sn的宏观偏析.     

Ni-P合金化学镀复合稳定剂优化试验研究

确定了化学镀Ni-P合金工艺试验技术路线,选取影响工艺性能的3个工艺参数,设计了L9(34)正交试验方案,探讨了各种稳定剂化学镀对Ni-P合金镀液和镀层性能的影响,用极差法分析了各工艺参数对工艺性能影响的主次顺序,确定了最佳工艺配方,优化验证试验结果表明:该工艺不仅镀层性能优良,而且镀液镀速高、稳定性好,具有很好的推广应用价值.     

Hardness variation and corrosion behavior of as-plated and annealed Cr-Ni alloy deposits electroplated in a trivalent chromium-based bath

Cr-Ni alloy deposits with various concentrations of Cr, Ni were obtained with different electroplating current densities in a plating bath containing trivalent chromium and divalent nickel ions. The Cr-rich alloy deposit with a very high hardness of 1150 Hv can be obtained by annealing at 700 °C for 30 min. These alloys displayed poor corrosion resistance due to through-deposit cracking during annealing. For optimal hardness and corrosion resistance, we recommend a sequential two-step electrodeposition with Ni-rich alloy electroplating followed by Cr-rich alloy electroplating, or Cr/Ni alloy electrodeposition, to create a protective coating.     

Studies on electrochemical deposition of novel Zn–Mn–Ni ternary alloys from an ionic liquid based on choline chloride

Ternary Zn–Mn–Ni alloy coatings were electrodeposited for the first time from a choline chloride based ionic liquid with the aim of collecting properties of binary Zn–Mn and Zn–Ni alloys into one alloy system. The effect of electrodeposition potential on the composition and corrosion performance of the obtained ternary Zn–Mn–Ni deposits was investigated and contrasted with the characteristics of Zn–Mn and Zn–Ni deposits. Cyclic voltammetry revealed that the deposition of ternary Zn–Mn–Ni alloys behaved differently from the deposition of binary Zn–Mn and Zn–Sn alloys and that Mn deposition takes place at positive potentials in the Zn–Mn–Ni electrolyte than in the Zn–Mn electrolyte due to the presence of Ni²⁺ ions in the electrolyte. X-ray diffraction studies showed that the Zn–Mn–Ni ternary alloys consist of a lattice of Zn (with Mn and Ni imbedded inside) at low electrodeposition potentials and MnZn(with Ni imbedded inside) phase at high electrodeposition potentials. Chemical composition analysis show that the Mn content in the ternary Zn–Mn–Ni alloy increased with increase in electrodeposition potential, whereas Zn and Ni contents are suppressed. The corrosion tests results indicate that through addition of Ni into the Zn–Mn binary alloy, the Zn–Mn–Ni alloy tailored are more corrosion resistant than the Zn–Mn binary alloy whilst the passivation behavior is still preserved.     

Free-Cyanide Synthesis and Characterization of Cu–Zn Alloy by an Electrodeposition-Annealing Route

Substitution of cyanide in electroplating is a current challenge. We present an alternative method aiming to reduce the toxicity and the cost of electroplating of Cu–Zn alloy (usually prepared from cyanide baths) while maintaining the decorative qualities and anticorrosive properties of the coating. For this purpose, Cu–Zn alloys were obtained in two steps from non-cyanide electrolytes. First, a copper layer electrodeposited onto a nickel under-layer, followed by a thin layer of zinc from three different simple non-cyanide zinc baths. The Zn/Cu/Ni sandwich system was then subjected to heat treatment at a temperature of 400°C, to ensure the diffusion of zinc into the copper layer to give the desired Cu–Zn alloy structure. The synthesized films were characterized by using X-ray diffraction XRD, scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). XRD demonstrated that the electrodeposited films are crystalline and present the Cu_0.7Zn_0.3 phase with preferential (111) orientation. An analysis of XRD patterns revealed that after heat treatment, the Cu–Zn alloys were composed of a predominating α-phase structure. The morphology and composition of the coatings depends on the zinc plating bath type. After annealing, well defined pseudospherical Cu–Zn grains were formed covering the entire substrate surface. The EDS analysis indicated the formation of Cu_0.7Zn_0.3 brass alloys. The results showed the feasibility of this low-cost new route for the preparation of good quality Cu–Zn alloys from cyanide-free electrolytes.