Rapid Firing of 3YSZ: Impact of the Heating Rate on Sintering, Properties and Microstructure

Ultrafast high-temperature sintering (UHS) is currently emerging as a powerful tool to consolidate ceramics in the seconds/few minutes timescale. It employs graphite felts as resistive heating elements that, due to the low thermal capacity, can be heated to ultrahigh temperatures in a matter of seconds.
Herein, we report the ultrafast high-temperature sintering of yttria-stabilized zirconia (YSZ). The results show that effective densification can be attained in a very short time scale and at temperatures significantly lower than that required for conventional sintering. Such an effect is attributed to the microstructural refinement induced by rapid heating when treating nanograined YSZ powders (particle size about 20 nm). On the other hand, the heating rate impact on densification is reduced when considering green bodies obtained with coarser powders. In this case, analytical models extrapolated during conventional heating can be used to predict the densification also under extreme heating rates.
UHS can also be integrated with additive manufacturing techniques to produce small components with complex shapes. In particular, we show that fused filament fabricated YSZ gyroids can be debinded and sintered by UHS within one minute obtaining bodies with properties analogous to those obtained by conventional firing.
Finally, we show that “reactive UHS” of YSZ with an N2-containing atmosphere is possible, allowing a fine tailoring of the material composition, structure, and properties with a specific focus on the ionic conductivity of the sintered components.

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Biography

Dr. Mattia Biesuz is an Assistant Professor of Materials Science and Technology at the University of Trento (Italy). He contributed to the research in the field of non-conventional sintering of ceramics, including flash sintering, cold sintering, and ultrafast high-temperature sintering. For his research in the field of firing, he was awarded the “Robert L. Coble Award for Young Scholars” (American Ceramic Society, US), “The MRS Postdoctoral Award” (Materials Research Society, US), and the “Pfeil Award” (IOM3 Institute of Materials Minerals & Mining, UK). Other research interests include chemical tempering, high entropy ceramics, polymer-derived ceramics, and thermal energy storage. He authored 100+ manuscripts and serves as associate editor in Materials, Frontiers in Materials, and the Journal of the American Ceramic Society.