X-RAY MICROTOMOGRAPHIC STUDIES OF METAL-MATRIX COMPOSITES USING LABORATORY X-RAY SOURCES

X-ray microtomography (XMT) is a non-destructive technique that allows the internal structure of a material to be imaged by the spatial dist ribution of its linear X-ray absorption coefficients. This paper demon strates the use of XMT to investigate: (1) the distribution of TiB2 re inforcement in composites formed by powder processing; (2) the local v oid volume fraction as a function of position in highly deformed regio ns of failed tensile specimens of Sic reinforced material allowing a v alid damage parameter to be defined at high strains; (3) absorption co efficients measured at different energies simultaneously using a multi channel analyser which can sometimes be used to separate linear absorp tion changes due to (a) density variations and (b) compositional varia tions in individual voxels; and (4) the use of sequential sections to provide a three-dimensional representation of the failed specimens.