The impact toughness of closed-cell aluminum foam with various densities was investigated. The impact load history revealed an elastic region followed by a rapid load drop region. The peak load and impact toughness of aluminum foam increases exponentially with density. The power exponents for impact toughness test are greater than that for compressive test. Fracture analysis indicated a mixed-rupture mode of quasi-cleavage and small shallow dimples. It can be attributed to the complex state of stress of notched specimens and elevated impact velocity under impact loading.

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The magnesium-based foam biomaterials were prepared by melt foaming process, where Mg-Ca alloy was used as matrix material, hydroxyapatite (HA) as tackifier, MgCO3as foaming agent. The magnesium-based foam biomaterials with uniform structure were used for testing to investigate their compressive and biodegradable behaviors. The biodegradable property of the magnesium-based foam was mainly characterized by microstructure observation and hydrogen evolution. The results showed that the porosity of the magnesium-based foam has a more important impact on yield stress and plateau stress of compressive curves compared to HA content or its size. Corrosion rate of the magnesium-based foams decreases with increasing HA addition. Meanwhile, the porosity of the magnesium-based foams also has a very obvious effect on hydrogen evolution, i.e., the hydrogen evolution rate increases with decreasing the porosity of magnesium-based foams.