Quasi-static uni-axial compression behaviour of hollow glass microspheres/epoxy based syntactic foams

Hollow glass microspheres/epoxy foams of different densities were prepared by stir casting process in order to investigate their mechanical properties. The effect of hollow spheres content and wall thickness of the microspheres on the mechanical response of these foams is studied extensively through a series of quasi-static uni-axial compression tests performed at a constant strain rate of 0.001 s−1. It is found that strength of these foams decreases linearly from 105 MPa (for the pure resin) to 25 MPa (for foam reinforced with 60 vol.% hollow microspheres) with increase in hollow spheres content. However, foams prepared using hollow spheres with a higher density possess higher strength than those prepared with a lower one. The energy absorption capacity increases till a critical volume fraction (40 vol.% of the hollow microspheres content) and then decreases. Failure and fracture of these materials occur through shear yielding of the matrix followed by axial splitting beyond a critical volume fraction.

► Deformation behaviour of syntactic foams is similar to bending dominated structures.
► The uni-axial compressive strength and density of these foams decrease linearly with filler content.
► Foams with high density filler have higher strength than those prepared with low density filler.
► Failure and fracture is through shear yielding of the matrix and axial splitting beyond critical volume fraction.