MATERIALS
Microstructural and Mechanical Performance of SiO₂-Reinforced Nickel-Based Nanocomposite Coatings
Nickel-based nanocomposite coatings reinforced with silicon dioxide (SiO₂) nanoparticles are attracting increasing interest in advanced marine applications due to their superior mechanical properties and resistance to surface wear. In this study, selective Ni-SiO₂ nanocomposite coatings were prepared and investigated to determine the relationship between microstructure, composition, and mechanical properties. The microstructure of the coatings was investigated using scanning electron microscopy (SEM). The analysis showed that the matrix is fine-grained and relatively homogeneous, containing well-dispersed SiO₂ nanoparticles at an amount corresponding to the optimal reinforcement level. Energy-dispersive X-ray spectroscopy (EDS) analysis confirmed that silicon oxide had been successfully incorporated into the nickel matrix and was uniformly distributed within it, and no significant signs of agglomeration were observed in the most effective compositions. Mechanical properties were evaluated by scratch tests to assess the coating’s adhesion and resistance to mechanical damage. The results showed that SiO₂-reinforced coatings exhibit significantly higher scratch resistance and higher critical load values. This improvement is attributed to dispersive strengthening, grain refinement, and the barrier effect created by hard ceramic nanoparticles, which together inhibit plastic deformation and crack propagation. In summary, the results of the study demonstrate the potential of Ni-SiO₂ nanocomposite coatings as durable protective solutions in marine environments, where resistance to mechanical wear and surface damage is particularly important. The study provides insights into how to adjust the microstructure and reinforcement distribution to improve the coating’s performance characteristics.