Analysis of Ceramic Composites by 3D Microtomography
In the first part we describe the use of 3D X-ray microtomography for the analysis of density distributions inside and between cold pressed green state whisker reinforced Si3N4 / Si3N4 bending test specimens. The differences between a changing content of whisker volumes (0 to 35 %) show a sharp density reduction between 10 and 15 %. This agrees with previous research which shows that maximum density is achieved between 10 and 15 % whisker loadings. Since density is directly related to fracture strength, microtomography may be useful as strength prediction.
In the second part we describe the use microtomography combined with image processing, especially a 2D FOURIER transform, for the analysis of cloth direction distributions in multidirectional reinforced chemical vapor infiltrated (CVI) SiC / SiC test components. The SiC fibers were NICALON™ and were oriented 30, 60, and 90°. In laying up the cloth, orientations may not be maintained and this impacts the mechanical properties. Use of microtomography with image processing may allow mechanical property variations to be established.
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