Enhancing loss modulus of carbon fibre polymer matrix composites by addition of particles in interlaminar region

The addition of tin-zinc (Sn-9Zn) particles of size 25-45 μm to a continuous carbon fibre epoxy matrix composite in the interlaminar region has resulted in a hybrid composite containing 10 vol.-% particles and exhibiting a loss modulus of 2 GN m^-2 and a density of 2.0 g cm^-3 for a longitudinal flexural specimen. The particle addition increased the loss modulus by > 20 000% and the density by 34%. The loss modulus increase was due to an increase in the loss tangent (tan δ), which more than compensated for the decrease in the storage modulus. For a transverse flexural specimen (a configuration that has no practical use), the loss modulus was decreased by the particle addition by about 60%, owing to decreases of both tan δ and the storage modulus.