The Effect of Oxygen on Copper Dissolution during Cathodic Polarization

The effect of oxygen on the anomalous dissolution of copper in acidic chloride media is studied. An increase in the copper corrosion rate during cathodic polarization in the potential range from –0.4 to –0.7 V is attributed to stirring of the near-electrode layer by evolving hydrogen bubbles. An addition of surface-active tetrabutylammonium iodide shifts the overpotential of hydrogen evolution and eliminates this effect. The copper dissolution rate during cathodic polarization is shown to be directly proportional to the reduction rate of dissolved oxygen. It is shown experimentally that H₂O₂ does not affect the dissolution rate of copper during cathodic polarization. The latter fact makes it possible to assume that oxygen reduction stages, which involve hydrogen peroxide, do not affect the anomalous dissolution of copper.     

负极集流体表面处理方法及对电池性能的影响

在高能扣式碱性锌锰电池负极集流体表面制备出一种性能良好的高氢过电位材料Zn-In合金.采用线性扫描阴极极化曲线、X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)、交流阻抗(EIS)及电池气胀高度检测等方法研究Zn-In合金材料的性质、各组分的含量以及对电池性能的影响.结果表明:该Zn-In合金材料显著提高了集流体析氢过电位,从而有效地抑制电池气胀, 改善电池性能,同时降低生产成本,且对环境友好,因此用于代替In电沉积具有广阔的应用前景.     

基于低共熔溶剂电沉积铁纳米晶体：过电位、氢键给体对形貌的影响

系统研究铁在3种低共熔溶剂中的电沉积行为以及过电位和氢键给体对铁沉积物形貌的影响。结果表明,在DES1和DES2中,过电位对铁沉积物形貌没有明显影响,但在DES3中过电位对铁纳米粒子的形貌有显著影响。此外,研究结果还证实了氢键给体的种类对铁沉积物的形成有着密切的联系:尿素氢键给体有助于片状网络结构铁膜的形成;乙二醇氢键给体有助于准球形铁纳米粒子的形成;而乙二醇和丙二酸氢键给体的协同作用有助于空心球和类毛线球状等纳米粒子的形成。     

Synopses of Papers

Abstract

The effect of anodic polarisation on dissolution of copper in hydroxylamine based chemical systems has been studied using a quartz crystal microbalance technique to evaluate their use in electrochemical mechanical planarisation processes. Copper dissolution in hydroxylamine solution increases with respect to overpotential η and dissolution rates as high as 600 nm min^–1 have been obtained at an overpotential of 750 mV. The effectiveness of benzotriazole (BTA) in inhibiting copper dissolution in these chemistries was also tested. It was found that BTA is effective in inhibiting copper dissolution only at lower overpotentials (≤250 mV).     

Adsorption of thiourea on polycrystalline platinum: Influence on electrodeposition of copper

Although previous works have shown the marked influence of thiourea as an organic additive in electrolyte bulk on copper electrodeposition, a variety of mechanisms could be responsible. The present paper concerns the effect of a thiourea layer adsorbed prior to copper electrodeposition. First evidence of a monolayer on platinum substrate was revealed by X-ray photoelectron spectroscopy. Two different times (15 h and 1 min) for platinum immersion were tested, and it was observed that, even for short times, thiourea is chemisorbed on the surface. Then, effects of thiourea adsorption on copper underpotential deposition (UPD) and overpotential deposition (OPD) processes on polycrystalline platinum were investigated by polarisation curves, atomic force microscopy and X-ray photoelectrons. Thiourea monolayer increases the copper UPD process: in fact the current density of UPD cathodic peak is higher in the presence of thiourea on the platinum surface. However no modifications were observed on the AFM images and on the XPS spectra. For the copper OPD process, the presence of thiourea monolayer inhibits copper deposition: the current density of OPD cathodic peak is lower whatever the immersion time of the platinum substrate in the thiourea solution. Moreover, XPS spectra show that the presence of thiourea modified the oxidation state of the copper coating, as an oxide film is formed more quickly on the surface of the coating.     

纯铝在NaCl溶液中活化溶解时电化学行为研究

通过动电位扫描、交流阻抗和恒电位集气的方法研究了纯铝在含Zn2+、In3+、Sn2+、Ga3+活化离子的0.5mol/LNaCl溶液中电化学行为,研究表明这些离子促进了铝电极在中性NaCl溶液中的活化,同时抑制了铝的负差数效应,其中Zn2+和In3+对铝的活化和抑制负差数效应呈现为协同作用,比照Al-Zn-In牺牲阳极研究了Zn2+和In3+协同作用机理,并进一步探讨了铝电极负差数效应机制.     

CALCULATION OF ELECTROCHEMICAL OVERPOTENTIAL AND CONCENTRATION OVERPOTENTIAL BASED ON CURVE OF ANODIC POLARIZATION IN HYDROGEN STORAGE ALLOY ELECTRODE

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On the Electrodeposition of Tungsten-Cobalt Alloys From Aqueous Solutions

Sound coherent deposits of tungsten-cobalt alloys with up to 60–66 wt. % of tungsten can be produced at cathode current efficiencies of up to 21% from solutions containing 40–70 g./l. of tungsten as sodium tungstate, 4–12 g./l. of cobalt as cobalt sulphate, 70–150 g./l. of citric acid and 50 g./l. of ammonium chloride, adjusted to room-temperature pH of 7·5–8·5 with sodium hydroxide, and operated at 50–70° C. with interrupted d.c. pulses of 0·05–2 sees, and equal or rather greater “off” periods, the cathode current density during the pulses being 5–20 amps./dm.². Moderate agitation of the solution is desirable.

Hydrogen overpotential for hydrogen deposition from citrate buffers is much less on tungsten-cobalt cathodes than on tungsten or cobalt cathodes. Evidently the electronic structure of the alloy cathodes is much more favourable than that of tungsten for hydrogen deposition: this suggests that it is also more favourable for tungsten deposition, which may help to explain why tungsten-cobalt alloys are so much more easily deposited than pure tungsten.

A number of amphipathic organic molecules, among them thiourea, benzenesulphonamide and pyridine, increase the hydrogen overpotential on tungsten-cobalt alloys: but they do not increase the cathode current efficiency of alloy deposition, evidently because they increase the metal-deposition overpotential about equally.     

钛-铜复合棒的主要生产方法及其基本特点

重点介绍了拉伸法、挤压或挤压 拉伸法、爆炸或爆炸 轧制法等钛铜复合棒材的生产方法及其基本特点。并分析了生产方法对产品质量的影响。     

AZ91D镁合金电偶腐蚀的研究

在自来水和3.5%NaCl溶液中测试了铸造AZ91D镁合金与铝合金、锌合金、Q235碳钢和Cu偶合后的电偶腐蚀行为,研究了腐蚀环境、偶接材料和阴阳极面积比(CAAR)对铸造AZ91D镁合金电偶腐蚀行为的影响。在电偶腐蚀过程中测量溶液的pH值以及电偶腐蚀电流;用失重法计算了铸造AZ91D镁合金的电偶腐蚀速率,利用SEM观察了AZ91D镁合金的腐蚀形貌,并对腐蚀产物进行XRD分析。结果表明,AZ91D镁合金在电偶腐蚀过程中会使溶液的pH值升高,并伴有以Mg(OH)₂为主的腐蚀产物的生成;溶液中Cl^-的存在会加速AZ91D镁合金的电偶腐蚀速率;低氢过电位金属Q235碳钢和Cu对AZ91D镁合金的电偶腐蚀加速效果明显高于中氢过电位金属铝合金和锌合金,偶接材料的极化性能对AZ91D镁合金的电偶腐蚀速率有较大影响。同时,大的阴阳极面积比会加速AZ91D镁合金的电偶腐蚀速率,且AZ91D镁合金的电偶腐蚀电流随阴阳极面积比的增大而呈线性增长趋势。     

Effect of Asymmetric Hot Rolling on the Texture Evolution of Fe–3%Si Steel

In Fe–3%Si steel, the hot rolling process affects not only the hot rolling texture but also the primary recrystallization texture. Here, the effect of asymmetric hot rolling was studied by comparing the difference in the texture evolved between asymmetric and symmetric hot rolling. The effect of asymmetric hot rolling on the texture of primary recrystallized Fe–3%Si steel was also studied. The symmetric hot rolling of Fe–3%Si steel produces a rotated cube texture at the center but Goss and copper textures near the surface. Asymmetric hot rolling tends to produce Goss and copper textures even at the center like the texture near the surface. After primary recrystallization, the dominant texture at the center changes from {001} <210> to {111} <112> and the new texture has a higher fraction of the grains which make the low energy boundary with Goss grains than that of symmetric hot rolling.     

铜包铝复合棒材平辊轧制宽展变形行为

对铜包铝复合棒材平辊冷轧时的金属流动进行数值模拟和实验研究.结果表明:由圆断面至扁断面的第一道次平辊轧制中侧边以变形宽展为主;在后续道次的平辊轧制过程中,滑动宽展的影响增大,侧边变形宽展的影响减小;当压下率为13.3%～26.7%时,摩擦因数对铜包铝棒材宽展率的影响较小,而当压下率大于33.3%时,摩擦因数对宽展的影响增大;铜包铝复合棒材的最大轧制压力在轧制入口端,断面上存在一条"X"状的等效应变带.实验结果与有限元分析结果具有良好的一致性.采用合适的轧制工艺,可获得铜包覆层分布均匀、铜铝复合界面无裂纹和分层、表面质量好的扁排.     

COLD ROLLING AND RECRYSTALLIZATION TEXTURE OF CROSS SHEAR ROLLED COMMERCIAL COPPER

The texture change along the normal direction to rolling plane of cross shear rolled commer-cial copper has been studied by means of two step method for ODF caleulation and computersimulation.The texture of cross shear rolling of copper is similar in primary components tothat of conventional cold rolling,but the scattering degree and direction of the texture are dif-ferent,due to the residual shear strain change in different position along the normal to rollingplane.It seems that no more effect of the shear strain upon the recrystallization texture.     

溶液中添加In~(3+)对铝电极负差数效应的影响

通过动电位极化、恒电位集气方法研究对纯铝在0.5mol/LNaCl溶液中的电化学行为,添加In3+后,使铝的活化电位负移,并且降低铝的负差数效应系数,提出铝溶解的动力学机制.探讨了In3+使铝电极在中性介质中抑制负差数效应的原因     

氢分离合金冷轧成膜组织演变及透氢性能研究进展

第VB族（Nb、V、Ta）难熔金属与商用Pd比不但具有较高的氢渗透率而且价格低廉，成为人们青睐的新一代可替代钯的新型氢分离膜材料。为了规模化制备高通量的氢分离合金膜，研究者们对铸锭合金先进行冷轧变形以获得大尺寸平面膜，然后通过退火处理提高渗透率从而达到合金膜通量效率提升的目的。本文从合金的冷轧成形性、轧态及后续退火态组织演变以及透氢性能三方面的研究进展进行综述，分析了冷轧成膜的成分效应，阐述铸态、冷轧态和退火态的微观组织与渗透率的关系。讨论了通过轧态后续退火改善组织结构，进而开发高通量氢分离合金膜研究所面临的问题，最后对冷轧成膜及后续退火是实现低成本可规模化制备低厚度、高渗透率氢分离合金膜的前景进行展望。     

冷轧铜铝复合板结合界面残余应力分析

针对冷轧铜铝双层板金属的变形特征以及各轧制工艺下界面残余应力的分布情况,采用有限元计算方法,分别将轧制速度、异径同步、异径异步各工艺产生的界面残余应力进行分析。研究结果表明,冷轧铜铝双层板的复合变形过程可分为4部分;铜板复合面的应变直接影响复合效果;异径同步轧制铜铝复合板时,随着辊径比的增大,铜板复合面的总变形量增大,当辊径比大于1．6时,总变形的增量不明显,辊径比取1．4~1．6时,残余应力较小;异径异步轧制铜铝复合板时,随着辊径比的增大,铜板复合面的总变形量增大,轧制速比取1．2~1．4时,残余应力较小。     

Pressure leaching of metals from waste printed circuit boards using sulfuric acid

Printed circuit boards (PCBs) are essential components of electronic equipments which contain various metallic values. This paper reports a hydrometallurgical recycling process for waste PCBs, which consists of the novel pretreatment consisting of organic swelling of PCBs followed by sulfuric acid leaching of metals from waste PCBs. To recycle the waste PCBs, experiments were carried out for the recovery of copper from the crushed and organic swelled materials of waste PCBs using sulfuric acid leaching in presence of hydrogen peroxide under atmospheric and pressure condition. The leaching of PCBs at 90°C, pulp density 100 g/L under atmospheric condition, using 6M sulfuric acid resulted in the dissolution of a minor amount of copper due to the presence of plastic coating on the surface of metallic layers. On the other hand, when the liberated metal sheets from organic swelled PCBs were treated with dilute sulfuric acid of concentration 2M along with hydrogen peroxide in an autoclave under oxygen atmosphere, the percentage recovery of copper was found to increase from 59.63% to 97.01% with an increase in hydrogen peroxide concentration from 5 to 15% (v/v) keeping constant pulp density 30 g/L.     

铜电解添加剂的工业监控

研究了铜电解精炼过程中添加剂工业监控的原理和方法.研究结果表明:阴极过电位是电解液性质的实时反映,通过阴极过电位的工业监控可得出不同电解条件时,添加剂最佳量的控制,从而在复杂铜电解过程中使高纯阴极铜生产的稳定性提高了6%;平均电流效率提高了1%.     

Effect of microstructural inhomogeneities on the evolution of texture during rolling and recrystallization of copper

Microstructural inhomogeneities in polycrystalline copper was intentionally varied by the deformation at the liquid nitrogen temperature and the rolling without lubrication. The effect of different rolling conditions on the evolution of microstructure and texture during rolling and subsequent recrystallization was studied by means of X-ray texture measurement and microstructural observations. Applying cold rolling at a low temperature led to the formation of deformation twins in grains at the Cu-orientation, and shear bands developed when cold rolling was performed without lubrication. The evolution of the normal rolling texture was suppressed by deformation twinning. Shear bands in deformed structure resulted in a very weak cube-recrystallization texture.     

A Study of Benzotriazole as an Addition Agent for Acid Copper Sulphate Solutions

During a study of addition agents for acid copper sulphate solution, it has been shown that benzotriazole forms an insoluble cuprous complex which codeposits with the copper^1a A method has been devised for dissolving the deposit and separating the addition agent and it has been deffionstrated that benzotriazole can be recovered from the electrodeposit in the undecomposed form.² Since benzotriazole can be separated and estimated with accuracy, it provides a compound which is eminently suitable for studying addition agent action during electrodeposition. Polarization studies have shown that benzotriazole markedly increases the activation overpotential of the cathode η_A—mainly by decreasing the active area of the surface by film formation—and it is possible to detect 10^?7 M benzotriazole from its effect on the cathode overpotential. Additions of 0·012 g/1 benzotriazole give very fine grained deposits of copper and prevent epitaxy, while higher concentrations (0·12 g/1) result in fully-bright deposits with a banded structure. The effect of plating variables on the amount of benzotriazole included in copper deposits has been studied as a necessary prerequisite for suggesting a mechanism of addition agent action which, in this particular system, has been based on the formation of metal complexes.