Study of Corrosion Behavior of Ni-W-B Alloy from Tartrate Bath by EIS in NaCI Solution

Nickel-Tungsten-Boron alloy (W-Ni-B) deposition is a potential substitute for hexavalent chrome. It has excellent wear, corrosion, and mechanical properties and may also be less of an environmental risk. The electro deposition of Ni-W-B alloy is obtained from plating baths containing tartrate. Optimum conditions for plating including current density, temperature and pH were studied. The corrosion resistance and amorphous character was also evaluated. The corrosion behavior ofNi-W-B coating on mild steel has been evaluated during exposure to 3.So/oM NaCI for different immersion time using potentiodynamic polarization and Electrochemical Impedance Spectroscopy measurements. The Ni-W-B alloy has higher Impedance values than Ni alone, thus confirming the higher corrosion resistance of the former.

Keywords:

EIS , Alloy Electro deposition , Corrosion , Ni-W-B Alloy , Tartrate