Compression deformation behaviour of aluminium matrix syntactic foams under quasistatic loading: In situ SEM compressive tests

In situ SEM observation was carried out during the whole quasistatic compression process to investigate the energy absorption mechanism of fly ash/aluminium syntactic foam. The results indicate that the damage appeared on the wall of cenospheres, leading to a local stress concentration, and then a crack band formed. Once cenospheres were collapsed layer by layer along the crack band, the syntactic foam engendered visible macroplastic strain at a near constant stress level. The macroplastic strain was caused by the collapse of cenospheres, which is the main mechanism of aluminium matrix syntactic foam as an energy absorption material.