Observation of fibers in long fiber reinforced metal matrix composites by x-ray computed tomography using synchrotron radiation

Four types of MMC reinforced with B and SiC fibers were observed by X-ray CT using synchrotron radiation. Use of X-ray CT made possible the direcl observation of fibers and defects in them. On the basis of X-ray coefficients of the elements in the composites the energy values of 21 and 29 KeV were selected for Al alloy and Ti alloy, respectively.The innerfiber and debonding parts of the interface between fiber and matrix were clearly observed for the composites used in this study. In the case of the silicon carbide reinforced aluminum composites, the core carbon fibers of 30µm in diameter were also observed. The resolution of X-ray CT scanner used in this study was about 10µm.3-dimensional images were reconstructed from several CT images. The 3-dimensional images visually displayed the inner structure and were very useful in discussing the model of the fracture process of the fibers contained in the metal matrix composites.