(174f) Synthesis and Characterization of Novel Ni-B-Y2O3 Composite Coatings

Ni-B coatings have decent properties such as high hardness, wear resistance and promising anti-corrosion properties which make them suitable for automotive, aerospace, petrochemical, textile and electronics industries. Despite these promising properties, further improvement in their properties is essential so that more challenging requirements and new developments can be fully addressed. Taking a note of the above contemplation, novel Ni-B-Y₂O₃ composite coatings were synthesized through electrodeposition process. In the present study, a comparison of structural, thermal and mechanical properties of Ni-B and Ni-B-Y₂O₃ composite coatings is presented to elucidate the useful role of Y₂O₃ addition to Ni-B matrix. XRD analysis confirms the amorphous nature of Ni-B coatings in their as deposited state. However, there is considerable improvement in crystallinity by the addition of Y₂O₃ particlesintoNi-B matrix. SEM analysis demonstrates the formation of uniform and fine-grained deposits in both coatings. However, AFM studies disclose that addition of insoluble Y₂O₃ into Ni-B matrix increases the surface roughness. Finally, it is also noticed that mechanical properties (hardness and modulus of elasticity) of Ni-B matrix can be significantly improved by incorporation of insoluble, hard ceramic particles (Y₂O₃) which make them attractive for many applications. This improvement in mechanical properties of Ni-B matrix can be attributed to the strong dispersion hardening effect of Y₂O₃ hard particleswhich hinders the movement of dislocations.