Effect of SWCNTs content and relative density on the energy absorption capabilities of closed-cell Al-cenosphere-SWCNTs hybrid foam

Abstract Al-Cenosphere-SWCNTs closed cell hybrid foams (HFs) of varying relative densities ( ρ r d ) were synthesized through stir casting technique using TiH2 (0.6 wt % of alloy) as a foaming agent, processed SWCNTs (0, 0.1, 0.2, 0.3 and 0.4 wt %) and cenosphere (4.25 wt % or 15 vol %) as thickening agent. Cenosphere particles provided micro-porosity within the cell wall and its shells act as reinforcement. It was noted that the addition of SWCNTs and Cenosphere improved the mechanical properties such as elastic modulus ( E f ) , plastic collapse stress ( σ p c ) , plateau stress ( σ p l ) and, energy absorption capabilities ( E a b ) of HFs. In HFs these properties increases with increase in SWCNTs up to 0.3 wt % and a further increase in SWCNTs content leads to the reduction of these properties of HFs. It is interestingly observed that the densification strain ( e D ) for a constant ρ r d is almost invariant to the SWCNTs content. The mechanical properties of the AFs and HFs foamsareempirically simulated and also compared with standard existing models for the different SWCNTs contents and ρ r d . The deformation mechanism has been examined during compression test.