Mechanical properties of model vitreous carbon foams

Abstract

The present paper deals with the relations between structural and physical properties of model vitreous carbon foams, i.e., presenting different porous structures in terms of bulk density, cell size and connectivity, while having the same composition and the same carbon texture. Herein, their mechanical properties were investigated through a comparative analysis of samples either with or without rigid plates glued to their opposite faces and submitted to quasi-static compression. Both methods led to the same values of compressive strength, which followed the Gibson and Ashby (G&A) equation for open-cell foams. The compressive modulus of both reticulated foams and cellular foams tested without plates only depended on the density and also followed the relation of G&A for open-cell foams. For cellular foams with plates, the relation of G&A for closed-cell foams applied with different values of φ, which is the percentage of solid only contained in the struts. Usually, only two types of foams are considered but it was highlighted here that a third type is of great interest: the semi-open-cell foams, which can be optimised through the values of both relative density and φ.