Numerical simulation and experimental investigation of combinatorial electrodeposition of Ni‐Cu material library using modified Hull cell

Abstract

Phone: þ91 (0)40 2301 6096, Fax: þ91 (0)40 2301 6032Numerical simulation of single run electrodeposition of Ni-Cu material library fabricated from citrate plating bath in a modified Hull cell is carried out at an applied average current density of 2 mA cm À2 by considering multiple electrode reactions. These electrode reactions include reduction of copper ions and nickel ions and hydrogen generation reaction along with influence of diffusion of metal species and Butler-Volmer kinetic rate equations. From the model, partial and total current densities, alloy compositions, and current efficiencies during codeposition of Ni-Cu alloy as a function of position on the working electrode is predicted. Ni-Cu thin film combinatorial material library is also fabricated experimentally under similar conditions used in the simulation. An acceptable agreement is noticed from the comparison of the simulated results with experimental data. Scanning electron microscopy (SEM) studies reveal the distinct changes in the surface morphology of the films at different positions on the substrate. The measured room temperature electrical resistivity values for the fabricated material library at 2 mA cm À2 are compared with the reported data of the metallurgical processed bulk Ni-Cu alloys and found that there is a relatively good match between them.Combinatorial strategy used for fabrication of Ni-Cu material library through electrodeposition.

Sediment deposition model of grading electrode in water cooling circuit of HVDC converter valve

“…So the electrochemical model considering the diffusion and electro migration of corrosive ions has been proposed. The electrode reaction mainly happened at the heterophase interface between electrodes and deionised water [16, 17]. The surface kinetics of electrode reaction is described by Bulter–Volmer equation, which is given by: where i loc ,m denotes the local charge transfer current density for electrode reaction m , A/m 2 ; i o,m the exchange current density at bulk concentrations for each reaction m; and are anodic and cathode transfer coefficients of reaction m , the overpotential, V ; E eq the equilibrium potential for reaction m , V ; R the universal gas constant.…”