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Engineering Science and Materials

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1997

Electrodeposition

Articles 1 - 7 of 7

Full-Text Articles in Chemistry

The Electrochemical Behavior And Deposited Mechanism Of Zn Ni Alloy Codeposition, Jixun Wu, Yongqin Liu, Huimin Meng Aug 1997

The Electrochemical Behavior And Deposited Mechanism Of Zn Ni Alloy Codeposition, Jixun Wu, Yongqin Liu, Huimin Meng

Journal of Electrochemistry

The electrochemical behavior of Zn Ni alloy codeposition and concomitant hydrogen evolution have been studied in the chloride ammonia solution through the d c electroplating method. Under the condition of the applied cathodic current density of 2A/dm 2 , the AC impedance spectra have been measured. An equivalent circuit has been presented for the impedance study on the alloy codeposition.


Behavior Of Copper In Hydrogen Storage Alloy Microencapsulated By Copper, Dawei Zhang, Huatang Yuan, Huabin Yang, Zuoxiang Zhou, Yunshi Zhang Aug 1997

Behavior Of Copper In Hydrogen Storage Alloy Microencapsulated By Copper, Dawei Zhang, Huatang Yuan, Huabin Yang, Zuoxiang Zhou, Yunshi Zhang

Journal of Electrochemistry

Negative electrode made from Cu microencapsulated hydrogen storage alloy was studied by using cyclic voltammetry method. The results showed that copper as a coating material was of a certain stability in 5 mol/L KOH solution within the range of charge and discharge voltage. But when expanding the sweep voltage, the CV curve showed a pair of distinct oxidation reduction current peaks of Cu 2O formation at E =-0.3 V and Cu 2O reduction at E =-0.6 V. With charging discharging cycles, copper is liable to be oxidized to Cu 2O and further oxidized into CuO 2- 2. When charged again, …


Studies On Electrodeposition Of Rare Earth Metals And Their Alloys In Molten Salts, Qiqin Yand May 1997

Studies On Electrodeposition Of Rare Earth Metals And Their Alloys In Molten Salts, Qiqin Yand

Journal of Electrochemistry

The cyclic voltammetry, convolution voltammetry, potentiostatic electrolysis and open circuit potential time curve after electrolysis, current time curve at potential step, potential time curve at current step, X ray diffraction, EDAX, electron probe microanalysis were used to investigate the electrode processes of the reduction of rare earth ions on inert electrodes and alloying electrodes in molten chlorides and fluorides. The free energies of formation for the intermetallic compounds, the diffusion coefficients of rare earth ions in the melt, the diffusion coefficients of rare earth atoms in the alloy phases were determined. The alloys of rare earth with iron, cobalt, nickel, …


Study Of Electrodepositing Bright Tin Cobalt Zinc Alloy From Weak Acid Solution, Zhengzhong Zuo, Runxiang Hou, Shaochun Xia May 1997

Study Of Electrodepositing Bright Tin Cobalt Zinc Alloy From Weak Acid Solution, Zhengzhong Zuo, Runxiang Hou, Shaochun Xia

Journal of Electrochemistry

A new process of electrodeposting bright Tin Cobalt Zinc alloy from weak acid solution is proposed in this paper. The solution compositions and operating conditions are Na 3C 6H 5O 7·2H 2O 100~150,Na 2EDTA·2H 2O 20~30,SnCl 2·2H 2O 15~20,CoSO 4·7H 2O 25~35,ZnCl 2 15~20 g·L -1 ;stabilizer WDZ 1 60~100, brightener WDZ 2 15~20 mL·L -1 ; pH=4~6, D K = 0.5~5.0 A·dm -2 , T= 5~35 ℃. A bright Sn Co Zn deposit having Co about 0.5~3.5% and Zn about 1~10% is produced. The effects of bath compositions on Co or Zn content in deposit is also discussed.


Electrodeposition Of Amorphous Fe Cr Alloy Coating, Danhong Cheng, Weiyi Xu, Yiqin Qin, Liqun Hua, Zhongyan Zhang May 1997

Electrodeposition Of Amorphous Fe Cr Alloy Coating, Danhong Cheng, Weiyi Xu, Yiqin Qin, Liqun Hua, Zhongyan Zhang

Journal of Electrochemistry

The amorphous Fe Cr alloy coatings were obtained by controlling the composition of bath operation conditions. It was found that the pH value, the current density and the content of chromium in Fe Cr alloy coatings effect the amorphous structure of the coatings. The result of anodic polarization shows that the corrosion resistance of the amorphous coatings in acidic media is higher than the corrosion resistance of the crystal ones.


Studies On The Cathodic Current Efficiency In The Electrodeposition Ni Psz Gradient Coating, Jun Li, Dianlong Wang, Li Chen, Xinguo Hu Feb 1997

Studies On The Cathodic Current Efficiency In The Electrodeposition Ni Psz Gradient Coating, Jun Li, Dianlong Wang, Li Chen, Xinguo Hu

Journal of Electrochemistry

The cathodic current efficiency and the electrochemical behavior in electrodeposition Ni PSZ gradient coating were investigated by various electrochemical techniques and scanning electron microscope. The results showed that the Ni PSZ composite coatings can accelerate evolution of hydrogen with the increase of PSZ content. The overpotential of nickel reduction will be increased and that of hydrogen reaction will be reduced in the presence of PSZ particles in electrolyte. The effect of PSZ particles on nickel electrodeposition was preferentially to catalyze the formation of H ads . These all contributed to the lower current efficiency.


A Study On The Electrodeposition Of Palladium And It′S Nucleation, Fangzu Yang, Shukai Xu, Shibing Yao, Bingyi Chen, Xueqing Zheng, Xiaohui Zhong, Shaomin Zhou Feb 1997

A Study On The Electrodeposition Of Palladium And It′S Nucleation, Fangzu Yang, Shukai Xu, Shibing Yao, Bingyi Chen, Xueqing Zheng, Xiaohui Zhong, Shaomin Zhou

Journal of Electrochemistry

The electrodeposition and nucleation of palladium are studied in the system of potassium citrate and ammonium oxalate. The results show that, with the additives of XP 4 and XP 7 prepared in our laboratory, a full bright palladium electrodeposits will be obtained in the wide ranges of the cathode current densities 0.5~3.5 A/dm 2 and temperature 40~60 ℃; the qualities of the thick deposits will be effectively improved by means of pulse current plating. Cyclic voltammograms results show that the division of peaks between anodic and cathodic on the electrode process of palladium will be up to 1.05 V, which …