Caracterização eletroquímica de ligas metálicas amorfas DE Ni-W-P.

Abstract

This work was carried out a study on electrodeposition of Ni-W-P alloy cell in Hull, is trying to simulate the conditions obtaining in the same industry. Thus, alloys were obtained in wide ranges of current density, and evaluated their physical properties, chemical, and resistance to corrosion. The physical and chemical characterizations were made by Scanning Electron Microscopy (SEM; VEGA-XMU; TESCO) and Energy Dispersive X-ray (EDX, attached to SEM) respectively. The corrosion resistance was evaluated using the techniques of Potentiodynamic Linear Polarization (PLP) used to determine the potential of corrosion using a postentiostato / Galvanostatic Autolab PGSTAT30 connected to a computer by the software GPES (General Purpose Electrochemical System) and the technique of Electrochemical Impedance Spectroscopy (EIS) that works with alternating-current signals and voltage according to the frequency, and is particularly sensitive to small changes in the system, such as layer thickness, porosity, crystallinity, and others. For measures of EIS was used postentiostato / Galvanostatic Autolab, model PGSTAT30, connected to a computer by the FRA. The electrodeposits with best features of adhesion, uniformity and stability in terms of composition were obtained by applying a current of 1.0 Amp and 70 °C. From this study it was found that the process of electrodeposition of alloys on an industrial scale may be feasible, since in different operating conditions of the current density were obtained from alloys with similar characteristics in relation to chemical composition, morphology and resistance to corrosion.