2D and 3D Characterization of Metal Foams Using X-ray Tomography

Abstract

The aim of this paper is to present a methodology for 2D and 3D characterization of different foams using X‐ray microtomography with a resolution of 30 micrometer. 2D and 3D quantitative image analyses have been performed to obtain information about the cells. The main parameters of interest are the cell size, the cell size distribution, morphology of the cells, connectivity of the cells, and fraction of matter at the edges. We use morphological operations such as opening granulometry to separate cells when they are not perfectly closed. This characterization was performed on Alporas, IFAM, and Norsk‐Hydro foam.

Fracture mechanisms and size effects of brittle metallic foams: In situ compression tests inside SEM

“…7, the largest cell (marked X max ) is located near the center of the visible face. It has been reported that the permanent deformation or fracture starts predominantly in the regions with the highest concentration of defects and the lowest local densities [17][18][19][20], and regions with these characteristics are usually occupied by the largest cells. In the case shown in Fig.…”

“…In general a metallic foam can be characterized on three scales [12][13][14][15][16][17][18][19][20]: the microscopic scale, which mainly deals with microstructures in cell walls; the mesoscopic scale, which mainly deals with the morphology, deformation and fracture in the cell and cell-wall level; and the macroscopic scale, which mainly deals with the collapse behaviour (e.g., deformation bands) and mechanical properties in the bulk-foam level. Gibson and Ashby [12] pointed out that although mechanical properties of metallic foams do concern with the micro and meso structure, the related parameters are difficult to be expressed in analytical models and impracticably to be checked once in use.…”

“…Usually the nondestructive imaging of collapse behaviour of metallic foams rely 0266 on surface observation. As a powerful tool, X-ray tomography is recently adopted to acquire the mesoscopic structures from three dimensions [17,18,20,23]. Maire et al [17,23] acquired 3D numerical images by high resolution X-ray tomography to study the microstructure and also the damage of different cellular materials.…”

“…They also examined several method of finite element modeling based on the acquired images. Elmoutaouakkil et al [18] quantitatively characterized the cellular morphology of metallic foams in terms of cell size/volume distribution, cell wall thickness distribution, with the help of X-ray microtomography. McDonald et al [20] employed the same method to collect three-dimensional images of aluminum closed-cell foam from the in situ compressive deformation experiment, and suggested not only the position of large cell volumes to be very important in the local concentration of stress, but also the distribution of cell volumes of immediate neighbours.…”

Correlation-based multi-shape granulometry with application in porous silicon nanomaterial characterization

“…Recently, mathematical morphology-based granulometry has been used to analyze 3D images, most of them obtained using X-ray tomography or focused ion beam tomography [13][14][15]. We think that the fundamental ideas presented in our paper can be applied to 3D images.…”