Observation of internal structure of ceramics and slurry by optical coherence tomography

Abstract

Optical coherence tomography (OCT) is an observation technique utilizing optical interferometry. Images of the internal structure of opaque materials can be obtained dynamically and three-dimensionally in a few seconds. In this work, the internal structures of ceramic sintered body and slurry was observed by OCT. In the case of Al2O3 ceramics, an artificially induced spherical defect having smaller than 50 μm in diameter which lies 700 μm below the top surface was observed successfully. Furthermore, it was observed that the internal structure of Al2O3 slurry was drastically changed during drying, followed by formation of a crack in the dried green body.