Experimental and Numerical Evaluation of the Enhancement Effect of Metallic Nanoparticles on Epoxy Composites

Epoxy is widely used in protective coatings due to its excellent adhesion, chemical resistance, and processing versatility; however, its inherent brittleness limits mechanical durability and wear resistance in demanding service environments. This study investigates the reinforcing effect of ZnO, CuO, and TiO 2 nanoparticles incorporated into an epoxy system at 0.5, 1.0, and 1.5 wt%, using a combination of mechanical mixing and ultrasonication to minimize agglomeration. The nano‐enhanced epoxies were evaluated through viscosity, hardness, tensile, flexural, abrasion, and accelerated weathering tests. Statistically significant improvements in tensile and flexural strength were confirmed by one‐way ANOVA with Dunnett's post hoc test ( p < 0.05), with 1.0 wt% identified as the optimal concentration in most cases. CuO produced the greatest enhancement in tensile strength, TiO 2 exhibited the highest abrasion resistance, and all three nanoparticles yielded comparable flexural improvements at optimal dosages. Nanoparticle addition also reduced surface roughness and modified viscosity, reflecting improved coating compactness and processability. At higher concentrations, performance declined in some systems, attributed to nanoparticle agglomeration. Representative volume element (RVE) modeling was further conducted to simulate tensile and abrasion responses at the microscale, with numerical results aligning well with experimental data and offering insight into stress transfer, strain distribution, and particle–matrix interactions.