Structure, Microhardness and Corrosion Properties of the Electrodeposited Ni-BN Nanocomposites

This study investigates the co-deposition, characterization and applications of nickel/boron nitride (Ni/BN) nanocomposites prepared by electrodeposition on copper plate from an ethylene glycol-based electrolyte. The main objective was to evaluate the impact of boron nitride (h-BN) incorporation on the corrosion resistance, surface morphology, microstructure and microhardness of the nickel matrix. Powder X-ray diffraction (p-XRD) analysis shows the layout of nanocrystalline coatings with grain refinement observed upon BN incorporation. A shift in preferred orientation and lattice strain indicated successful particle incorporation without phase transformation. Scanning electron microscopy (SEM) shows that Ni/BN coatings manifest finer, smoother, and more compact surface morphologies than pure Ni coatings. Vickers microhardness testing showed a significant increase in hardness with BN addition, reaching maxima of 415 HV at 1.0 A/dm² because of dispersion strengthening and grain boundary pinning effects. Potentiodynamic polarization analysis in 3.5 wt% solution of NaCl demonstrated enhanced corrosion resistance of the Ni/BN nanocomposite coatings compared to Ni, attributed to the barrier effect of uniformly distributed BN nanosheets and enhanced passive film stability. The results suggest that electrodeposited Ni/BN nanocomposites are better materials for applications requiring improved mechanical strength and corrosion resistance.