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T. Konegger, M. Kappa, A. Liersch, M. Scheffler:
"Computer-tomographical assessment of the pore evolution in PDCs";
Talk: 8th Pacific Rim Conference on Ceramic and Glass Technology, Vancouver, Kanada; 05-31-2009 - 06-05-2009.

An inherent characteristic of many polymer-derived ceramics is the formation of pores due to gas evolution and change in density throughout the process of pyrolytic conversion. The presence of pores in a bulk material has direct influence on mechanical properties such as strength, hardness and fatigue.
With microcomputer tomography (µ-CT), a non-destructive evaluation of the material´s microstructure in general and the development of the pore structure in particular is possible. This method allows the three-dimensional imaging of bulk materials with resolutions in the sub-micron range.
A special focus was set to the pore structure evolution of polysilazane-derived ceramics with oxide ceramic fillers. Zirconia and alumina-loaded polysilazanes were crosslinked and pyrolyzed at different temperatures. After each temperature step µ-CT measurements were carried out and the pore formation was calculated. From the results the thermal conversion process was evaluated, and a porosity profile over the cross section and the parameters of thermal treatment was generated.
From these results a fine tuning process of the pyrolysis parameters is possible since the cracks and failures can be addressed without materials destruction in a wide parameter interval.

polymer-derived ceramics, computed tomography