Study of Deformation and Erosion Behaviour of Epoxy-Glass Microballoon Based Syntactic Foam

Abstract

The present work is focused on the synthesis and study of the deformation behavior of epoxy resin/glass microballoonbased syntactic foams. Different densities syntactic foams with 0 to 40 volume percentages of glass microballoons were prepared by stir-casting method for the present investigation. The high viscosities of the resin-microballoons mixture (putty like consistency) beyond 40 volume percentage prevents processing of higher microballoon content syntactic foam. The effect of glass microballoon content on tensile, compression, flexural and impact properties were studied in detailes. The results show that specific tensile strengths of the foam was increased by about 34% along with the reduction in density (by about 38%), starting from pure resin to foams with 40% glass microballoon. It is also found that compressive strength of the foam decreases from 140 MPa (for pure resin) to 75 MPa (with 40 vol.% reinforcement). During tensile loading, deformation occurs predominantly through shear yielding of the resin matrix followed by debonding at the matrix-microballoon interface. The crushing of the glass microballoons and subsequent densification of the foams is responsible for large amount of plastic strain during compressive deformation. The erosion behavior of the syntactic foam is also investigated as a function of the different glass microballoons content. Three different erodent velocities (48, 70, 82 m sec-1) and three different angles of impingement (30o, 60o and 90o) are used as experimental parameters in the present investigation. The erosion rate is found to be highest for 40 vol.%reinforcementas compared to pure resin due to presence of larger amount of hollow glass microspheres.