Porous structures of ZrO₂ Fiber Insulation Tile Revealed By Synchrotron X-Ray In-Line Phase Contrast Microtomography

Zirconia (ZrO₂) aerogels show excellent insulating performance and have been widely applied as a thermal protector in furnaces, nuclear reactors, and spacecraft. The nondestructive determination of their interior microstructure is significant for evaluating their mechanical and insulating performance. In this study, we perform a nondestructive structural investigation of ZrO₂ fiber insulation tile by using synchrotron X-ray in-line phase contrast microtomography at a pixel resolution of 6.5 µm. Taking advantage of the edge enhancement of phase contrast imaging, single ZrO₂ fibers are clearly distinguished; furthermore, interior aggregates are nondestructively observed at this spatial resolution. This work demonstrates the advantages and potentials of synchrotron X-ray microtomography for the structural analysis of porous ceramic materials. By combining more brilliant synchrotron radiation sources and CCD detectors with higher spatial and temporal resolutions, we anticipate that we can further understand the relationship between aerogel microstructures and functions, especially under in-service conditions at high temperatures. Through this understanding the heat insulation performance and mechanical stability of ZrO₂ aerogels will be eventually improved.