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1.
Ivonne Sgura Amos S. Lawless Benedetto Bozzini 《Inverse Problems in Science & Engineering》2019,27(5):618-647
The process of electrodeposition can be described in terms of a reaction-diffusion partial differential equation (PDE) system that models the dynamics of the morphology profile and the chemical composition. Here we fit such a model to the different patterns present in a range of electrodeposited and electrochemically modified alloys using PDE constrained optimization. Experiments with simulated data show how the parameter space of the model can be divided into zones corresponding to the different physical patterns by examining the structure of an appropriate cost function. We then use real data to demonstrate how numerical optimization of the cost function can allow the model to fit the rich variety of patterns arising in experiments. The computational technique developed provides a potential tool for tuning experimental parameters to produce desired patterns. 相似文献
2.
《中国有色金属学会会刊》2021,31(12):3800-3813
The Fe−Ni−TiO2 nanocomposite coatings were electrodeposited by pulse frequency variation. The results showed that the nanocomposite with a very dense coating surface and a nanocrystalline structure was produced at higher frequencies. By increasing the pulse frequency from 10 to 500 Hz, the iron and TiO2 nanoparticles contentswere increased in expense of nickel content. XRD patterns showed that by increasing the frequency to 500 Hz, an enhancement ofBCC phase was observed and the grain size of deposits was reduced to 35 nm. The microhardness and the surface roughness were increased to 647 HV and 125 nm at 500 Hz due to the grain size reduction and higher incorporation of TiO2 nanoparticles into the Fe−Ni matrix (5.13 wt.%). Moreover, the friction coefficient and wear rate values were decreased by increasing the pulse frequency;while the saturation magnetization and coercivity values of the composite deposits were increased. 相似文献
3.
In the present work, inter-diffusion of nickel and titanium and formation of Ni-Ti intermetallic compounds on Ti-6Al-4V substrate have been studied. Initially, nickel was electrodeposited on the alloy using a modified Watts bath solution at a current density of 2 A dm?2 for 1?h. The coated specimens were then heat treated for different durations at 750, 800 and 850 °C under argon atmosphere. The effects of temperature and time on the characteristics, hardness and wear resistance of intermetallic phases were investigated. The results showed that a multilayer structure was formed after heat treatment, an outer layer of residual nickel, an area of intermetallic layers with different compositions followed by a solid solution of Ni-Ti. It was also observed that an increase in time or temperature at first led to the formation of thicker intermetallic layers; however, after passing a critical point, the intermetallic layers seem to dissolve into the substrate. Furthermore, the wear rates of the diffusion treated samples were four times lower compared to Ti-6Al-4V alloy when sliding against AISI 52100 hardened steel. 相似文献
4.
5.
本文综合了近期有机试剂中电沉积铝的有关文献,主要介绍了铝在AlCl3与乙醚、四氢呋喃(THF)、1-甲基-3乙基咪唑氯化物(MEIC)、N-(n-丁基)吡啶氯化物(BPC)等满替代的翁盐等组成的电解质中,电沉积的电极过程,以及在MEIC和BPC中得到的铝层组织和结构的研究成果,并举例了沉积铝层的应用。 相似文献
6.
Jaspreet S. Gandhi William J. van Ooij 《Journal of Materials Engineering and Performance》2004,13(4):475-480
Organofunctional silanes recently have emerged as outstanding, environmentally friendly corrosion protectors for metal substrates,
compared with conventional chromate treatments. A simple immersion technique is typically used to coat the metal surface with
silane films. However, the thickness and uniformity of the films are uncontrolled in this process. This paper proposes a new
deposition technique for the silane films on the metal surface, i.e., by electrodeposition. Hydrolyzed silanes are water-soluble,
ionized molecules, so they can be deposited on metals by electrodeposition. Various combinations of silane mixtures were tested
at different voltages, pH values, bath concentrations, and exposure times on panels of alloy aluminum and mirror-polished
ferro-plate. The surface structure was characterized by scanning electron microscopy (SEM) and ellipsometry. The resistance
of the film to corrosion was investigated by direct current (DC) polarization and electrochemical impedance spectroscopy (EIS)
techniques. Electrodeposition results in a more organized and uniform film with fewer pores, compared with immersed or dipped
films.
This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September
15–17, 2003, in Indianapolis, Indiana, and appears on pp. 320–26 of the Proceedings. 相似文献
7.
利用二维Miedema坐标参数(Δφ~*和Δn_(ws)~((-1)/3))及加入尺寸因素ΔR/R_A构成的三维化学坐标揭示了水溶液法制备多元合金的非晶形成规律。对109个合金分析表明,在二维和三维坐标中,可分别由一直线和一平面较好的将非晶形成和非形成区区分;非晶化条件为:二维坐标系中,二元系,|Δφ~*|>6.4|Δn_(ws)~((-1)/3)|+0.05;多元系,|Δφ~*|>6.6|Δn_(ws)~((-1)/3)|+0.05。判据的准确率在二元、二元和三元以及二元、三元和四元合金系中分别为:81.9%,82.9%及83.5%;三维坐标系中,二元系,|ΔR/R_A|/0.6+|Δφ~*|/0.12-|Δn_(ws)~((-1)/3)|/0.02=1,多元系,|ΔR/R_A|/0.03+|Δφ~*|/0.1-|Δn_(ws)~((-1)/3)|/0.01=1。在二元及二元和三元系统中,区分的准确率高于82%以及86%;该判据扩展至四元合金系后,准确率仍高于86%。 相似文献
8.
碱性电镀光亮锌镍合金研究 总被引:3,自引:1,他引:3
研究了镀液的组成与镀层中镍含量、镀层的相结构以及阴极电流效率的关系。提出了碱性电镀光亮锌镍合金的最佳镀液组成和工艺规范,并对茴香醛、四乙烯五胺和ZN—A5添加剂的吸附行为及其对锌镍电沉积过程的阻化作用进行了探讨。 相似文献
9.
NICKEL ELECTROPLATING has been practicallyused for decades.There is an unknown part in theplating,although this is easy to plate.Applications ofthe plating are described from the practical viewpoint.Purpose of Nickel Electroplating(1)Decorative,and corrosion resistanceNickel electroplating is deposited on iron,cupper,zinc and aluminum substrate etc.,and chromiumplating is usually deposited on nickel plating.Hexavalent chromium plating has an important effecton the corrosion resisitan… 相似文献
10.
采用电化学恒电位沉积方法在ITO导电玻璃上和在ZnO薄膜上沉积氧化亚铜(Cu2O),并通过X射线衍射(XRD)和扫描电镜(SEM)对晶体的微观结构和表面形貌进行了分析.在ZnO基底上沉积得到了纳米级的Cu2O粒子并且具有明显择优取向,而在ITO导电玻璃上仅得到粒径为2—5胛的Cu2O粒子,没有明显的择优取向,对薄膜的生长机理进行了讨论. 相似文献