Effect of composing particles of two sizes on mechanical properties of spherical silica-particulate-reinforced epoxy composites

The correlation between compositions using particles of different two sizes and mechanical properties was studied experimentally. Spherical silica particles of 0.24 and 1.56 μm in diameter were compounded into a bisphenol A-type epoxy matrix at composition ratios ranging from 0 to 1.0 with a constant volume fraction, 0.30. Although varying the composition ratio of two-particle did not significantly affect the bending elastic modulus, the bending strength and fracture toughness were strongly dependent on the particle composition. The composition effect of different particle sizes on fracture toughness was clarified to have a difference from the one on bending strength, although elastic modulus varied according to volume fraction of particles.