Improvement in properties of Ni-B coatings by the addition of mixed oxide nanoparticles

Abstract

A comparison of properties of electrodeposited Ni-B and Ni-B-ZrO2-Al2O3 nanocomposite coatings is presented to explain the benefits of addition of mixed nanoparticles of ZrO2 and Al2O3 into Ni-B matrix. A comparative study of the properties of Ni-B and Ni-B-ZrO2-Al2O3 nanocomposite coatings in their as deposited condition indicates that the addition of mixed nanoparticles into Ni-B matrix has significant influence on its structural, surface, mechanical and electrochemical properties. Incorporation of mixed nanoparticles into Ni-B matrix shows significant grain refinement, substantial enhancement in mechanical properties and decent improvement in corrosion resistance. The improvement in mechanical properties can be attributed to grain refinement of Ni-B matrix and dispersion hardening effect of insoluble hard ceramic nanoparticles. Similarly, corrosion inhibition efficiency of binary Ni-B coatings is considerably improved which can be presumably regarded as the effect of formation of dense structure and decrease in active area of Ni-B matrix due to incorporation of mixed inactive nanoparticles. There is simultaneous improvement in mechanical and anti-corrosion properties of Ni-B coatings by the incorporation of mixed nanoparticles demonstrating usefulness of Ni-B-ZrO2-Al2O3 nanocomposite coatings for many applications.