Evaluation of joined silicon nitride by X-ray computed tomography (X-ray CT)

Abstract

X-ray computed tomography (X-ray CT) was performed to evaluate defects in a joined silicon nitride sample. The resolution of the X-ray CT was about 10 µm. ZrO₂ particles (ZrO₂ was added as a sintering additive), segregation of Zr, and cracks were successfully observed. These defects were most likely introduced during the fabrication procedure, i.e., by insufficient milling of the ZrO₂, separation of ZrO₂ in the slurry, and cracking during drying after slip-casting. X-ray CT is demonstrated to be a useful evaluation method, since these defects are introduced not only by joining but also by usual ceramics processing.