Novel Electrodeposited Ni-B/Y2O3 Composite Coatings with Improved Properties

Ni-B/Y2O3 composite coatings were developed through an electrodeposition process to study the effect of addition of Y2O3 particles on structure, surface, thermal, mechanical, and anticorrosion properties of Ni-B coatings. It is revealed that parent crystal structure of Ni-B matrix is preserved by addition of Y2O3, however, a noticeable improvement in crystallinity is observed. The analysis of the surface exhibits formation of dense and nodular deposits in the two types of coatings, but incorporation of Y2O3 particles in Ni-B matrix has resulted in a noteworthy change in grain size and surface roughness. Thermal analysis of the surfaces indicates that Ni-B-Y2O3 composite coatings demonstrate superior thermal stability compared to Ni-B coatings. The nanoindentation analysis shows a significant enhancement in the mechanical characteristics of the Ni-B matrix by addition of Y2O3 particles. This may be contemplated as the result of grain refinement and dispersion hardening of the Ni-B matrix by the presence of hard Y2O3 particles. A decent improvement in the corrosion protection efficiency (73.6%) is also observed by addition of Y2O3 particles into Ni-B matrix. Simultaneous improvement of mechanical and anticorrosion properties suggests potential applications of Ni-B-Y2O3 coatings in oil and gas, automobile, and many other industries.