Yang Fangzu

Electrodeposition and structure of Ni-W-B amorphous alloy

SUMMARY The electrodeposition of Ni-W-B alloy and the composition, structure and microhardness of the deposits were studied by means of electrochemical techniques. XPS, DSC and XRD. The results showed that Ni-W-B alloy electrodeposit has a lower electrochemical activity compared with Ni-W alloy. Ni-W-B alloy electrodeposition was accompanied by the electroless deposition of Ni and incorporation of Na2B4O7 in the deposit. The composition of Ni-W-B alloy deposit was not remarkably affected by changes of sodium tungstate concentration and the maximum electrodeposition current efficiency was 49.9% in the electrolyte solution with [W]/[W]+[Ni] mole ratio at 0·65. The Ni-W alloy obtained was present in a nanocrystalline structure. Ni-W-B was amorphous. Treatment at 400°C for 2 hours caused coarsening of grain size. phase evolution for the Ni-W-B alloy and increase of microhardnesses.

Initial Behavior of the Electroless Nickel Deposition on Pretreated Aluminum

National Natural Science Foundation of China [20873114, 20833005, 21021002]; National Key Basic Research Program of China (973) [2009CB930703]; Science and Technology Project of Fujian Province, China [2009H4020]

Application of Copper Electrochemical Deposition for the Metallization of Micropores

National Natural Science Foundation of China[20873114, 20833005, 21021002]; National Key Basic Research Program of China[2009CB930703]

Electrocrystallization of Cu-Sn Alloy on Copper Electrode Surface

National Natural Science Foundation of China [21021002]; National Key Basic Research Program of China (973) [2009CB930703]

Electrocrystallization of Pd-Ni Alloys on Glassy Carbon Electrode

Using the Scharifker and Hills model and Heerman and Tarallo model, cyclic voltammetry and chronoamperometry were used to study the nucleation mechanism upon the electrodeposition of a Pd-Ni alloy from an electrolyte. The results show that the electrodeposition of the Pd-Ni alloy onto glassy carbon electrode consisted of nucleation and growth, and the nucleation process according to the Scharifker and Hills model follows three dimension-progressive nucleation, which is controlled by the diffusion of the electroactive species. By applying the Heerman and Tarallo model, the kinetic parameters associated with the crystal nucleation and growth processes were obtained. The nucleation rate constant and the density of active nucleation sites increased from 0.83 to 7.71 s - 1