Alumina Influence on the Corrosion Resistance of Composite Layers Ni-P-Al2O3

Abstract

This paper aims to analyze the corrosion resistance of composite layers based on Ni-P matrix and disperse phase alumina of 10 µm size, present in amounts of 5, 10 and 20 g / L in the nickel plating bath. The influence of alumina on the corrosion resistance of Ni-P-Al₂O₃ composite layers was tested in 0.1 N hydrochloric acid solution compared to Ni-P layers with different phosphorus contents. The samples immersed in the corrosive environment were weighed every 7 days for 4 weeks. The corrosion rate was appreciated considering the loss of mass per area in time. Mass loss was calculated considering the total time of corrosion and the mass lost each week for determining the kinetics of the process. The variation curves of the corrosion rate are presented, depending on the chemical composition of the analyzed layers and the corrosion time.