3D characterization of the SiC nanoparticle distribution in ZrB₂–SiC ceramics with synchrotron X-ray nanoscale computed tomography

Evaluating the dispersion of SiC nanoparticles is significant for the development of ZrB₂–SiC nanocomposite ceramics. This paper reports the 3D distribution characterization of the nanosized SiC additives in ZrB₂–SiC ceramics with synchrotron X-ray nanoscale computed tomography (nano-CT) and Morisita indexes. Different from the investigation with electron microscopy, the presented work implements nondestructively 3D visualization and quantitative characterization of the SiC nanoparticles distribution in ZrB₂–SiC ceramics. Firstly, a ZrB₂–SiC ceramic sample with a size less than 60 μm was prepared. Then, a nano-CT experiment was designed and implemented for this sample at the 4W1A beamline of Beijing Synchrotron Radiation Facility (BSRF). Next, SiC nanoparticles were extracted by applying image segmentation to the generated 3D nano-CT images of this sample and visualized by volume rendering. Finally, Morisita index was extended from 2D to 3D and applied to the corresponding nano-CT images for the quantitative characterization of SiC nanoparticle 3D distribution. The results from the Morisita index are in good agreement with the visual observation. They reveal that SiC agglomerates exist in the ZrB₂ matrix and vary over the regions of interest in the investigated sample.