电镀法测表面应力

电镀法是在被测物表面镀铜或镀镍,在交变应力作用下,利用镀层内的组织变化来测定表面弹性应力应变的方法。本文简述电镀法原理,讨论其在实物交变应力及高温应力测量中的应用。     

Study on the changes of ultrasonic parameters over supercritical Ni-Co electroplating process

This work discusses the influence of changes to ultrasound (US) parameters over the nickel cobalt (Ni-Co) metal thin film properties produced by supercritical CO₂ (SC-CO₂) electroplating. Additionally, Ni-Co films were produced by conventional electroplating and silent SC-CO₂ and compared against each other.The discussion on metal thin film properties revolves around variations to the bath type ultrasonic power (15 W and 20 W) and frequency (42 k Hz and 72 kHz) during experiments. The properties provided by the three electroplating processes and analyzed include: grain sizes, film elemental content analyses, surface microstructures, film hardness, corrosion resistance, surface roughness, crystalline structure and preferential growth, etc. From the results it was clear that quality of films produced by US-SC-CO₂ was improved compared to that of films produced by silent SC-CO₂, which itself was better than those produced by conventional electroplating. However, when US power was varied we observed a decline in the mechanical properties of the produced films.The combination of ultrasonic agitation with SC-CO₂ allows for improved mechanical properties such as: lower surface roughness, finer grain size and surface morphologies, increased corrosion resistance and film hardness. The ultrasound agitation applied to SC-CO₂ electroplating enhanced the formation of alloyed metal as ultrasonic agitation increased the electrolyte flowability during electroplating process resulting in increased mass transfer while at the same time achieving a surface cleaning effect which removed metal ions with poor adhesion and other unwanted particles. Moreover, application of ultrasonic agitation avoids the use of surfactants so only changes to the physical phenomena and no changes to the chemical composition of the deposited thin films were observed, meaning less pollution to the electrolyte and higher purity of the deposited films.The US-SC-CO₂ electroplating method described in this work effectively enhanced the mechanical properties of the deposited thin films compared to those produced by both silent SC-CO₂ and conventional electroplating processes.     

电子功能外延薄膜的电沉积

电沉积作为一种在温和条件下从溶液中合成材料的技术已被广泛应用于在导体和半导体基底表面合成各种功能材料。电沉积一般由人为施加于基底的电刺激（如：施加电位/电流）来触发。这种电刺激通过氧化或还原靠近基底表面的溶液层内部的离子、 分子或配合物从而使该溶液层偏离其热力学平衡状态,随后引起目标产物在基底表面的沉积。在电沉积过程中, 许多实验参数都可能从不同的方面对沉积物的物化性质造成影响。迄今为止,已通过电沉积制备出多种单质（包括金属和非金属单质）、 化合物（例如：金属氧化物、金属氢氧化物、 金属硫化物等）以及复合材料。电沉积制备的这些材料大多为多晶、 织构或外延薄膜的形式。其中, 外延薄膜是一种具有特定的面外和面内晶体生长取向且其晶体取向受基底控制的类单晶薄膜。由于外延薄膜中高度有序的原子排列,它们常呈现出独特的电磁性质。本文总结了常见的电沉积合成路线及影响沉积物外延生长的关键实验因素。此外, 本文简要介绍了用于表征外延薄膜的技术。最后, 本文还讨论了一些采用电沉积制备的具有特殊电子、 电磁及光电特性的功能外延薄膜。     

阴离子表面活性剂聚二硫二丙烷磺酸钠的合成

利用硫化钠与硫磺反应制备二硫化钠,然后将二硫化钠与1,3-丙磺酸内酯反应,合成了一种可作为电镀添加剂的阴离子表面活性剂——聚二硫二丙烷磺酸钠(SPS)。采用核磁共振氢谱对合成产物进行结构表征,确认了产物结构及产率。通过正交试验研究了产物产率与反应物配比、反应温度、溶剂加入量等因素之间的关系,找出了最优合成条件:第一步合成二硫化钠的反应中,硫化钠/硫磺物质的量比为1∶1.3,温度55℃,加水量18 mL;第二步合成SPS的反应中,1,3-丙磺酸内酯/硫化钠物质的量比为1.7∶1,温度40℃,溶剂量75 mL,产物的最高产率可达到95.8%。     

晶体硅太阳电池双层电极优化分析与实验研究

相对于单层电极结构,优化的前表面双层电极能够明显减小功率损失,改善晶体硅太阳电池的电学特性．本文对晶体硅太阳电池的双层电极进行了优化分析和实验研究.通过扫描电子显微镜观测将双层电极的截面抽象为更接近于实际的半椭圆型,建立了太阳电池前表面的双层电极模型,理论分析了双层电极的电学损失和光学损失.结合丝网印刷后光诱导电镀太阳电池的实验,得到了理论和实验上的最优化光诱导电镀增厚电极厚度与丝网印刷电极宽度的关系.所得到的理论和实验结果符合良好.由于并不涉及电极制备的具体技术,双层电极理论模型普遍适用于多种类型的双层电极结构.     

Structural Analysis of Electroplated Amorphous-Nanocrystalline Ni-W

 Ductile nickel-tungsten (Ni-W) alloys containing about 20–21 at.%W were electroplated onto copper substrates. The development of the amorphous/nanocrystalline microstructure towards a complete crystallization by isochronal heat treatments in vacuum was monitored by different methods. For medium annealing temperatures a solid-solution of W in the fcc-Ni lattice was achieved resulting in an increased hardness. For temperatures of 600 °C and upward recrystallization started and thermodynamically stable intermetallic compounds like Ni₄W and NiW were formed. A third phase, containing more than 80 at.%W was also detected but could not be identified so far. Only by combination of different methods and especially by use of analytical TEM structural analysis and phase identification in these amorphous-nanocrystalline Ni-W alloys were successful.     

用接触电池原理处理含铬电镀废水

利用焦炭和铁屑在酸性含铬溶液中形成接触电池,使六价铬转化为三价铬,再在碱性液中把三价铬沉淀析出的方法,采用简单的设施对电镀厂含铬废水进行处理,以较少的投入达到国家废水排放标准。     

电镀液和电镀层中钯和钴的分光光度法同时测定

在ＰＨ＝４．５的ＨＡｃ－ＮａＡｃ介质中,钴和钯都能与２－「２－（６－甲基苯并噻唑）偶氮」－５－「Ｎ－甲基－Ｎ－乙羧基」苯甲酸（简称ＭＣＢ）形成络合物。在λ＝７１０ｎｍ处Ｃｏ－ＭＣＢ不吸收;在６１０．５ｎｍ处Ｃｏ－ＭＣＢ有最大吸收,而Ｐｄ－ＭＣＢ也有一定的吸收值。利用这一差异,在可６１０．５ｎｍ处测定Ｐｄ和Ｃｏ的合量,而在７１０ｎｍ处测定Ｐｄ的含量学与化学传感再利用系数法算出Ｃｏ的含量。测定了纯性范     

A study of direct- and pulse-current chromium electroplating on rotating cylinder electrode (RCE)

Direct- and pulse-current (DC and PC) chromium electroplating on Cr-Mo steel were performed in a sulfate-catalyzed chromic acid solution at 50 °C using a rotating cylinder electrode (RCE). The electroplating cathodic current densities were at 30, 40, 50 and 60 A dm⁻², respectively. The relationship between electroplating current efficiency and the rotating speed of the RCE was studied. The cross-sectional microstructure of Cr-deposit was examined by transmission electron microscope (TEM). Results showed that DC-plating exhibited higher current efficiency than the PC-plating under the same conditions of electroplating current density and the rotating speed. We found the critical rotating speed of RCE used in the chromium electroplating, above this rotating speed the chromium deposition is prohibited. At the same plating current density, the critical rotating speed for DC-plating was higher than that for PC-plating. The higher plating current density is, the larger difference in critical rotating speeds appears between DC- and PC-electroplating. Equiaxed grains, in a nanoscale size with lower dislocation density, nucleate on the cathodic surface in both DC- and PC-electroplating. Adjacent to the equiaxed grains, textured grains were found in other portion of chromium deposit. Fine columnar grains were observed in the DC-electroplated deposit. On the other hand, very long slender grains with high degree of preferred orientation were detected in PC-electroplated deposit.