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

Abstract 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.

[1]  P. Withers,et al.  Mapping the evolution of density in 3D of thermally oxidised graphite for nuclear applications , 2006 .

[2]  George Spanos,et al.  Combining Serial Sectioning, EBSD Analysis, and Image-Based Finite Element Modeling , 2008 .

[3]  J. Calo,et al.  Carbon porosity characterization via small angle neutron scattering , 2001 .

[4]  G. Peix,et al.  Relations between X-ray tomography, density and mechanical properties in carbon–carbon composites , 2001 .

[5]  Koen Janssens,et al.  Investigating morphological changes in treated vs. untreated stone building materials by x-ray micro-CT , 2008, Analytical and bioanalytical chemistry.

[6]  D. Ducassou,et al.  Application of novel techniques of medical imaging to the non-destructive analysis of carbon-carbon composite materials , 1983 .

[7]  P. Voorhees,et al.  Analysis of Complex Microstructures: Serial Sectioning and Phase-Field Simulations , 2008 .

[8]  L. Feldkamp,et al.  Practical cone-beam algorithm , 1984 .

[9]  P. Withers,et al.  The effect of thermal oxidation on polycrystalline graphite studied by X-ray tomography , 2005 .

[10]  E. Maire,et al.  On the application of x-ray microtomography in the field of materials science , 2001 .

[11]  S. Mauran,et al.  Gas flow through highly porous graphite matrices , 2003 .

[12]  Paul Mummery,et al.  Numerical modelling of the effects of porosity changes on the mechanical properties of nuclear graphite , 2006 .

[13]  Microstructural analysis of in situ mesophase transformation in the fabrication of carbon-carbon composites , 2006 .

[14]  T. Gustafsson,et al.  Neutron-scattering studies on carbon anode materials used in lithium-ion batteries , 2002 .

[15]  J. Schrooten,et al.  Validation of x-ray microfocus computed tomography as an imaging tool for porous structures. , 2008, The Review of scientific instruments.

[16]  J. Kieffer.  Investigation of the transitional pore structure of activated carbon fibers by small-angle neutron scattering , 1992 .