Effect of carbon nanofiber reinforcement on mechanical properties of syntactic foam

The effect of carbon nanofiber (CNF) content on mechanical properties of syntactic foams was evaluated experimentally. Compression, flexural, and fracture toughness tests were performed to observe the mechanical behaviors of CNF reinforced syntactic foams (CNFRSFs). Results showed that no enhancement in compressive strength with addition of CNFs was observed. The flexural strength and fracture toughness increased with the increase in CNFs content. The decreasing trend occurred beyond 1.5 vol% of CNFs addition, which is ascribed to the agglomeration and clustering of CNFs. The toughening mechanisms, such as crack deflection, step structure, and debonding were proposed and the specific properties of CNFRSFs were also discussed in this paper.