Characterization of the Compressive Behaviour of an Al Foam by X-Ray Computerized Tomography

Al metal foams manufactured by the powder-method have been investigated. Compression tests were performed on the same sample at increasing deformation steps: at each stage the sample was observed by X-ray computerized tomography. A geometric evaluation of porosity on many sections was performed by calculating, for each pore, its area, equivalent diameter, perimeter and circularity. During compression tests at first deformation occurs in the weakest zones of the samples, leading to cells collapse and densification that progressively propagates in a wide region until final densification. Going on compression, cells reduce progressively their dimensions: at each compression step it can be observed the disappearance of cells with the greatest equivalent diameter and the increasing of the number of cells with the smallest diameter. In particular at the last step the reduction of the total cells number occurs.