Investigate the impact of titanium dioxide nanoparticles on the micro-hardness performance of symmetric optimized stacking hybrid fiber reinforced polymer composite

Abstract

The integration of nanoparticles within fiber-reinforced polymer (FRP) composites has emerged as a promising strategy for improving their mechanical performance. In this study, the influence of varying the symmetric fiber stacking patterns and different concentrations of titanium dioxide (TiO2) nanoparticles on the micro-hardness behavior of hybrid FRP composites is systematically explored. Hybrid composites consisting of symmetric layers of carbon and glass fibers embedded in an epoxy matrix were fabricated using a hand lay-up technique, followed by compression molding. TiO2 nanoparticles were infused into the matrix at varying weight fractions (0, 1.25, 2.50, 3.75 and 5.0) to assess their influence on the micro-hardness characteristics of the composites. Micro-hardness tests were performed using the micro-Vickers hardness method in accordance with ASTM E384 standards. The findings indicate that among all symmetric hybrid composites, the ‘C3G7C3’ stacking pattern exhibited the highest hardness (51.86 Hv) along with the lowest mean diagonal (59.81 µm). The incorporation of TiO2 nanoparticles further enhanced the hardness of the ‘C3G7C3’ composite. When compared with the non-hybrid glass composite (G13), the optimized ‘C3G7C3’ hybrid showed a remarkable improvement in micro-hardness, achieving 140% and 212% higher values without and with 2.50 wt. % TiO2 nanoparticles, respectively. The scanning electron microscopy, morphological analysis of the indented and fractured regions revealed that the incorporation of up to 2.5 wt. % TiO2 in ‘C3G7C3’ composites results in fewer defects, suggesting improved interfacial bonding between the matrix and the fibers.