Influence of additives on corrosion resistance of electrochemical composite coatings Ni-B

摘要

The possibilities of producing corrosion resistant Ni-B composite coatings with boron as dispersed particles have been investigated. A Watts type nickel plating bath with low concentration of nickel ions (0.75 mol dm~(-3)) and additives were used for deposition of the composite electrochemical coatings. The results of investigations of composite coatings nickel-boron deposited from the bath containing 2; 5 and 10 g/dm boron were shown. The internal stresses, the content of particles in coatings, the surface morphology and the corrosion resistance of composite coating Ni-B were measured, Vo1tammetry was used for examination of the corrosion resistance of samples of composite coatings in 0.5 M NaCl. The additives used in the baths affected the surface morphology of the electrodeposited coating. The obtained results suggest that the content of incorporated boron particles increases with an increasing amount of boron in plating bath. All of the Ni-B composite layers had better corrosion resistance than the nickel coating.