Corrosion properties of the Ni-P/ MoS2 composite layers produced by electroless plating on the aluminum

The aim of this work is the evaluation of corrosion properties of composite Ni-P/MoS2 and nickel Ni-P layers deposited on an aluminum substrate by the chemical reduction method. The examinations of the morphology of the deposited coatings Ni-P and Ni-P/MoS2 and their deterioration rates after the corrosion tests were characterized using scanning (SEM) techniques. The polarization and electrochemical impedance spectroscopy (EIS) examinations were realized in the 0,5M solution of NaCl. Results of these examinations are reported and compared. The polarization curves (j = f(E)) and corrosion parameters have been determined by the potentiodynamic method. The impedance measurements were represented in the form of Nyquist and Bode diagrams. The equivalent electric circuits and their elements' parameters were determined. The performed investigations showed important infl uences of ceramic phase additions on corrosion properties of electroless Ni-P layers.