Preparation and properties of electrodeposited Ni-B-V2O5 composite coatings

Abstract

Coatings of Ni-B have gained significant importance in various industries owing to their major role in improving mechanical properties including hardness, conductivity, and wear resistance. Despite all these characteristic features, there is still the need for a lot of modifications. This is to improve the properties of the coating so as to increase their durability and overall performance. The current study is based on development of Ni-B-V2O5 composite coating on mild steel substrate through the electrodeposition technique and the investigation of mechanical and anti-corrosive properties of the formed coating. The incorporation of V2O5 particles into the composite coating was confirmed by energy dispersive spectroscopy. X-ray diffraction pattern showed amorphous nature of electrodeposited Ni-B matrix, while the crystalline nature improved with the addition of V2O5 particles to the composite. Field emission scanning electron microscopy and atomic force microscopic studies clearly indicated that the addition of V2O5 particles to the Ni-B coating increased the surface roughness. Further studies reveal increase in the micro-hardness (by 171.11%), and elastic modulus (by 9.4%) in case of the Ni-B-V2O5 composite coating relative to the Ni-B coating. The enhanced micro-hardness was attributed to the inclusion of hard V2O5 particles into the Ni-B matrix, which in turn, may inhibit the dislocation motion in the composite. An increase in corrosion resistance (by 229%) was also experienced in the electrodeposited Ni-B-V2O5 composite coating in comparison to the bare Ni-B matrix, which may be due to the masking of inert V2O5 particles on the active region of the Ni-B composite.