Effect of condensation product of glycyl-glycine and furfural on electrodeposition of zinc from sulphate bath

Zinc electrodeposition from sulphate bath was carried out in presence of condensation product formed between glycyl-glycine (GGL) and furfural (FFL). The bath constituents were optimized through Hull cell experiments. Operating parameters such as pH, temperature and current density were also optimized. Current efficiency and throwing power were measured. Polarization study revealed 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. IR spectrum of the deposit showed inclusion of condensation product in the deposit during plating. The consumption of brightener in the lab scale was 7 mLL⁻¹ for 1000 amp-h.     

Effect of condensation product on electrodeposition of zinc on mild steel

Electrodeposition of zinc on steel was obtained from acid chloride bath containing condensation products (CP) of 3,4,5-trimethoxy benzaldehyde (TMB) and chitosan (CTN). The effect of bath constituents, pH, current density and temperature on the nature of deposit was studied by Hull cell experiments. The bath composition and operating parameters were optimized. The adhesion, ductility and corrosion resistance of the deposits were discussed. Throwing power and current efficiency values under different plating conditions were measured. SEM photomicrographs of the deposit were taken to study the surface morphology. The inclusion of addition agent in the deposit was investigated from IR spectrum of the scrapped deposit. The consumption of brightener in the lab scale is 10 mLL⁻¹ for 1000 amp-h.     

A new condensation product for zinc plating from non-cyanide alkaline bath

Zinc electroplating from non-cyanide alkaline solution is carried out in the presence of condensation product formed between DL-alanine (DLA) and glutaraldehyde. The bath constituents and bath variables are optimized through standard Hull cell experiments. The current efficiency and the throwing power are measured. High shift of potential towards more cathodic direction was observed in presence of addition agents. Corrosion resistance test reveals good protection of base metal by zinc coating obtained from the developed electrolyte. SEM photomicrographs show fine-grained deposit in the presence of condensation product. IR spectrum of the scraped deposit shows the inclusion of the condensation product in the deposit during plating. The consumption of brightener in the lab-scale is 6 mLL^-1 for 1000 amp-hour.     

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.     

用于微机械器件的电镀Fe—Ni合金薄膜的研究

本文考察了非常规Ｆｅ－Ｎｉ合金电镀中,溶液浓度、电流密度、ＰＨ值和温度等因素对电镀的影响。实验结果表明,Ｆｅ－Ｎｉ合金电镀的异常性是由于Ｆｅ（ＯＨ）２对铁离子和镍离子的还原反应有着不同的阻碍作用和程度。用Ｘ射线平移法对Ｆｅ－Ｎｉ合金镀层的残余应力与电镀参数之间的关系进行了研究,并讨论了薄膜微结构与应力的关系。     

电沉积Zn-Ni-Sn合金工艺研究

采用碱性焦磷酸盐体系在电解铜箔上电镀Zn-Ni-Sn三元合金可改善铜箔表面的综合性能.通过研究主盐含量、pH值、温度、电流密度对镀层质量的影响,选择了合适的添加剂,并对其极化行为进行了研究,优化确定了电镀Zn-Ni-Sn三元合金的镀液组成和工艺条件.经过处理后的电解铜箔耐蚀性、耐热性和粘合强度等性能指标均有明显提高.     

A High Performance of ENi–P Coatings on Mechanical and Tribological Properties with Influence of Bath pH on AZ91 Magnesium Alloy

Electroless nickel–phosphorus (ENi–P) coating was carried out on AZ91 magnesium alloy substrates by varying the bath solutions pH. The ENi–P coating process was carried out with sodium hydroxide as the pH adjuster. The effect of bath pH values on surface characteristics and wear resistance properties were investigated after deposition on AZ91 magnesium alloy substrates. Three suitable bath compositions with different pH were prepared for coating the substrates. Encouraging results for ENi–P deposit were obtained when the bath pH value was maintained at 6.5. A smooth and uniform microstructure was observed in the deposit obtained from bath B (6.5 pH). It also enhanced the microhardness and wettability, while the surface roughness of the ENi–P deposit reduced considerably, thereby resulting in better wear resistance and also preventing regular or early failures, and improving service life.     

Electroless deposition of Ni-Co-B alloy films and influence of heat treatment on the structure and the magnetic performances of the film

The Ni-Co-B alloy was electrolessly deposited from the bath using potassium borohydride as a reducing agent and ethylenediamine as a stabilizer. The effects of the plating conditions on the plating rate and the composition of the deposit were studied to improve the stability of the plating bath and to control the composition of the Ni-Co-B deposit. The crystallization behavior of the deposit was investigated by X-ray diffraction. The results show that the structure of the as-plated deposit is amorphous, and the deposit was crystallized into cubic Ni₃B and Ni-Co phases at 350 °C. The effect of heat treatment on the magnetic performances of the deposit was studied by vibrating sample magnetometer. The saturation magnetization and the residual magnetization of the coating go up with the increase of heat treatment temperature from 50 °C to 600 °C. The deposit heat-treated at 600 °C is found to be suitable as soft magnetic materials.     

氟硼酸盐体系铅镉合金电沉积研究

应用是化学方法和SEM技术,研究了氟硼酸盐体系中铅,镉和铅－匐混合镀液的阴极化曲线及电沉积－镉合金的工艺条件,结果表明,镀液中添加间苯二酚和胨能显著提高氟硼酸体系阴极极化及改善镀层性能,脉冲电沉积与直流电沉积对比结果表明,脉冲电沈积镀层性能较直流电沈积有明显改善,原子吸收分光度法分析表明,直流和脉冲电沉积所得镀层镉含量均随电流密度的增加而增加。     

Fe-36%Ni软磁合金电沉积条件的研究

采用电沉积法制备Fe-36%Ni软磁合金薄膜,通过正交实验方法研究了Fe2 /Ni2 摩尔比、镀液pH值、电流密度、镀液温度与合金中铁含量的关系,用极差法分析了各工艺参数对Fe-Ni合金薄膜成分影响的显著性,并确定了最佳工艺条件.优化验证实验结果表明,所得合金薄膜光亮、致密、外观平整,合金薄膜中Fe含量为64.99%(质量分数),Ni含量为35.01%(质量分数),其饱和磁通密度(Bs)0.84T,剩余磁通密度(Br)0.27T,矫顽力(Hc)65A/m.     

Protective coating for magnesium alloy

A phosphate–permanganate conversion coating was applied as the pretreatment process for AZ91D magnesium alloy substrate. Zn–Ni alloys were electrodeposited onto the treated AZ91D magnesium alloy from sulfate bath. The morphology and phase composition of the coatings were determined with X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results reveal that the conversion rate depends on pH of solution and treatment time. Salt spray and the electrochemical polarization testing were applied to evaluate the corrosion performance of phosphate–permanganate and Zn–Ni coated alloys. It was found that Ni content in deposit is a function of current density and bath composition. Zn–13 wt.% Ni coating provides very good corrosion protective function to inner AZ91D magnesium alloy. Phosphate–permanganate treatment enhances the corrosion resistance of Zn–Ni coatings.     

The effect of pulse parameters in electro deposition of silver alloy

Pulsed electro deposition of silver alloy is aimed at the improvement of some properties like finer grain size, hardness, anti-tarnishing, lower porosity, improvement in surface property. The pulsed electro deposition of silver alloy has been analyzed from an alkaline cyanide bath with brightener. Pulse duty cycles of 20% to 80%, at frequencies 10 Hz, 25 Hz, 50 Hz and 100 Hz with peak current densities ranging from 1 A/dm² to 9.3 A/dm² are employed. The influences of pulse duty cycle, peak current density and pulse frequency on the thickness, hardness of silver deposit, and current efficiency of the plating process are studied. Good quality deposits (less porosity and fine grains) can be obtained at lower peak current density and higher duty cycle.     

Polynitroaniline as brightener for zinc-nickel alloy plating from non-cyanide sulphate bath

Electro-polymerization of orthonitroaniline was carried out on graphite electrode in hydrochloric acid medium. Zinc-nickel alloy deposition was carried out in the presence of polynitroaniline in acid sulphate bath. The bath constituent and bath variables were optimized through Hull cell experiments. The current efficiency and throwing power were measured. High shift of potential towards more cathodic direction was observed in presence of addition agent. Corrosion resistance test revealed good protection of base metal by zinc-nickel coating obtained from the developed electrolyte. SEM photomicrograph shows fine-grained deposit in the presence of addition agent. The consumption of brightener in the lab-scale was 0·01 gL⁻¹ for 1000 amp-h.     

NdFeB磁体表面化学镀Ni-Co-p合金及其耐腐蚀性能研究

采用化学镀方法制备Ni-Co-P三元合金镀层以改善NdFeB磁体的耐腐蚀性能.优化了镀液配方以及施镀工艺,研究了镀液pH值和金属离子配比([Co2 ]/[Ni2 Co2 ])对沉积速度和镀层成分的影响,测量了NdFeB基体和不同镀层在3.5%(质量分数,下同)NaCl溶液中的极化曲线.结果表明,随镀液pH值增加,沉积速度提高,镀层中Co含量升高,Ni含量和P含量逐渐降低;随镀液中Co2 比例增加,沉积速度下降,镀层中Co含量升高,Ni和P含量降低.化学镀Ni-Co-P合金后的NdFeB磁体在3.5%NaCl溶液中的腐蚀速度降低了约两个数量级;当镀液金属离子配比[Co2 ]/[Ni2 Co2 ]=0.3时,镀层耐腐蚀性能最好,且优于相同施镀条件下所得到的Ni-P镀层.     

聚丙烯塑料低温化学镀Ni-P工艺的研究

研究了Ni-P化学镀液的主要成分、pH值和温度工艺参数对化学沉积Ni-P合金镀层镀速的影响.通过选择合适的镀液成分和工艺参数,在PP塑料基体上低温化学镀Ni-P合金工艺中获得中磷含量合金镀层,探讨了镀液组分对镀层性能的影响,优化了工艺参数.利用扫描电镜测得镀层的含磷量为8.057%,所以为非晶态的镀层.     

电镀Ni－S合金的析出过程及非晶态结构的形成

研究了在含有硫代硫酸钠（Ｎａ２Ｓ２Ｏ３）的镀液中电镀Ｎｉ－Ｓ非晶态合金的条件。结果表明，Ｎｉ－Ｓ合金镀膜的成分随着电流密度、镀液中Ｎａ２Ｓ２Ｏ３的含量、镀液ｐＨ值的变化而变化，但镀膜结构则由镀膜中硫含量所决定。根据Ｘ射线衍射分析，含硫量为１５－３０ａｔ％的镀层具有非晶态结构。此外还对Ｎｉ－Ｓ合金镀膜的形成过程及电镀条件与镀膜形成的关系进行了研究。     

电沉积条件对Fe-Ni-P合金沉积的影响

为促进Fe-Ni-P合金电沉积层在信息存储材料和屏蔽材料中的应用,研究了pH值、电流密度等工艺条件对合金沉积速度、组成、表面形貌和结构的影响.结果表明:当镀液主盐物质的量比Fe/Ni=5/5时,随pH值从2.0增加到4.0,镀层中Fe原子分数从6.92%增加到64.47%,Ni从61.03%下降到8.07%,P从32.05%下降到27.46%;随电流密度从20 mA/cm2增加到50 mA/cm2,镀层中Fe原子分数从2.49%增加到63.15%,Ni从55.99%下降到13.50%,P从41.52%下降到23.35%.用X射线衍射和扫描电镜研究了镀层的结构和表面形貌,试验表明,所有镀层均呈非晶态结构,受工艺条件影响较小;随pH值从2.0增加到4.0,镀层表面的圆形颗粒粒径逐渐增大.     

化学镀Ni—W—B非晶质电阻膜的研究

研究了化学镀 Ni-W-B 合金的工艺及性能。结果表明,在 Ni-B 槽液中加入一定量的钨酸钠溶液,不仅能得到含 W、B 的镀层,而且还能提高镀液的沉积速度;Ni-W-B 合金层的电阻率随钨含量的增加而增大,随镀层厚度的增加而降低。     

Studies on electrosynthesized zinc mercury selenide alloys

Zn_1-x Hg _x Se ternary alloy thin films with x ranging from 0.14 to 0.5 have been deposited on conducting glass substrates by electrodeposition from aqueous bath containing ZnSO₄, HgCl₂ and SeO₂ at bath temperatures from 30 °C to 80 °C. The influence of deposition parameters on the crystallinity, composition, band gap and lattice constants of the film is studied. The films deposited at the potentials between −0.4 V and −1.0 V vs SCE at 70 ° C were characterized by X-ray diffraction (XRD), Energy dispersive X-ray (EDX), scanning electron microscope and optical absorption technique. Photoelectrochemical (PEC) solar cells based on Hg _x Zn_1-x Se thin film electrodes were constructed and the effects of annealing and photo etching on solar cell parameters were studied.     

表面活性剂PEG6000对二元络合体系化学沉积铜的影响

研究了表面活性剂聚乙二醇6000对乙二胺四乙酸(EDTA)/四羟丙基乙二胺(THPED)二元络合体系化学镀铜的过程和化学镀铜表面结构的影响。混合电位-时间测试结果表明,化学沉积过程分为三个区：诱发区、过渡区和稳定区。PEG6000使体系的混合电位负移趋势放缓,与表面活性剂在铜表面的吸附阻滞了对带电荷离子的吸附有关。线性扫描测试结果表明,阴极还原反应为控制步骤,PEG6000的吸附减缓了阴极还原反应,还原峰电流密度下降了约40%;铜化学沉积速率随着PEG6000浓度的提高呈线性下降趋势。SEM、EDS和XRD表征结果表明,化学镀铜的纯度较高,加入PEG6000使镀层呈现出明显的(220)晶面择优取向,且晶粒尺寸由77.7 nm减小到50.0 nm,有细化晶粒的作用。