A novel method for producing Al-foams and evaluation of their compression behavior

Closed-cell aluminium foams were produced by a melt foaming process using MgCa(CO3)2 (dolomite) as foaming agent. XRD analysis was used to follow the crystallization behaviour of the Al-foam which occurred during the foaming process. The compressive properties of these Al-foams and their deformation behavior were investigated. The structure and the mechanisms of failure were examined by scanning electron microscopy (SEM) supported with an in situ micro-test. Deformation is uniform and strain hardening is observed without a plateau stress. The strength of the Al-foams rises with increasing the relative density. Failure of the foams is mainly attributed to brittle fracture of the cell walls rather than to their plastic buckling leading in this way to a reduced energy absorption ability.