Comparison of X-ray micro-tomography measurements of densities and porosity principally to values measured by mercury porosimetry for carbon–carbon composites

X-ray Micro-Tomography (μCT) applied to carbon–carbon composites is shown to be able to quantify the amount, shape, and distribution in three dimensions of both open and closed porosity with a minimum dimension greater than 10 μm. Being a non-destructive technique, it is also able to track these values following each densification cycle. It is also demonstrated that μCT is able to obtain bulk density values for non-uniform samples as well as the same results for skeletal density as other techniques used conventionally. Furthermore, values for open porosity comparable to those obtained by mercury porosimetry can be obtained by X-ray Micro-Tomography if the value obtained by the mercury porosimeter is truncated below the resolution of the μCT. Finally, it is shown that in conjunction with data from the mercury porosimetry, μCT is also able to demonstrate the presence of “bottle-neck” pores i.e. open pores with restricted pore access dimensions.