Hollow-grained “Voronoi foam” ceramics with high strength and thermal superinsulation up to 1400 °C
Name
Hollow-grainedVoronoifoamceramicswithhighstrengthandthermalsuperinsulationupto1400C-1.pdf
Description
Accepted version
Size
1.77 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Li, Sa
Wang, Chang-An
Yang, Fuqian
An, Linan
So, Kangpyo
Li, Ju
Date Issued
2021
Journal
Materials Today
Publisher
Elsevier BV
Version
Author's final manuscript
Abstract
© 2021 Elsevier Ltd Nanostructures tend to be unstable at high temperatures due to large capillary energies, and therefore nanotechnology has not yet found many high-temperature applications at 1000 °C and above. By taking advantage of the high-temperature stability of refractory ceramics, here we develop a new approach of making hollow nano-grained materials to achieve thermal superinsulation across a wide temperature range, where the gaseous voids are mostly isolated within individual grain, with size comparable to the mean free path of air molecules to lower the thermal conduction by Knudsen effect. We have proved this general concept with hollow-grained La2Zr2O7 ceramic, and demonstrated exceptionally low thermal conductivity (0.016 W/(m⋅K)), the lowest ever reported for hard materials at or above room temperature. The centimeter-scale samples also have ultrahigh compressive strength (251 MPa), tensile strength in bending up to 100 MPa, and excellent thermal stability up to 1400 °C in air, due to monodispersity of pores that delays coarsening.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
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DOI of Published Version
https://doi.org/10.1016/j.mattod.2021.02.003
