High temperature deformation behavior of closed cell ZnAl27 hybrid foam made through stir casting technique

Closed cell ZnAl27 hybrid foam was synthesized through stir casting technique using CaH2 (0.5 wt%) as foaming agent and cenosphere particles were used as thickening agent and to create microporosity into the final structure. The relative density of the synthesized hybrid foam was found in the range of 0.20-0.30. Microstructural characterization was carried out to find distribution of cenosphere particles into the cell wall of hybrid foam. Compression tests were carried out to find out the effect of temperature, relative density and strain rate on the deformation behavior of the foam. It was found that each foamed sample displays three regions i.e., linear elastic, plateau and densification respectively. On the basis of stress-strain curves obtained at varying relative density, strain rate and temperature the values of plateau stress, energy absorption capacity and densification strain were calculated. It was found that according to the increase in relative density and strain rate the plateau stress and energy absorption capacity also increased. The effect of temperature on plateau stress and energy absorption capacity for lower relative density was more as compared to the higher relative density. The densification strain was almost invariant (0.02-0.03) on varying strain rate for the same relative density.