On the current percolation-induced hot-spot issue during flash sintering: The case of 8 mol% yttria-stabilized zirconia and Gd2Zr2O7 composites

Hot-spot creation during flash sintering is considered a key limitation for its industrialization. Establishing a method to predict this phenomenon can address this limitation. Here, a three-phase Gd2O3-m-ZrO2-8YSZ composite was designed to introduce a percolative current, and the induced hot-spot i...

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Bibliographic Details
Main Authors: Yue Cao, Guo-Cheng Xu, Federico Smeacetto, Ping Shen
Format: Article
Language:English
Published: Elsevier 2022-12-01
Series:Open Ceramics
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666539522000840
Description
Summary:Hot-spot creation during flash sintering is considered a key limitation for its industrialization. Establishing a method to predict this phenomenon can address this limitation. Here, a three-phase Gd2O3-m-ZrO2-8YSZ composite was designed to introduce a percolative current, and the induced hot-spot issue was systematically investigated. We show that the percolative current can be induced when the 8YSZ fraction reaches a certain value, but it will be suppressed as Gd2Zr2O7 generated at flash onset. On these bases, the effect of percolative current on sintering behavior was investigated by performing isothermal flash experiments. We demonstrated that hot spots tend to form in the presence of percolative current, and their size increases with increasing voltage. This was further distinguished with respect to onset power density, from which an abnormal rise was observed in the hot-spot samples. This finding was explained in terms of thermal runaway and could be considered an indicator of local heating.
ISSN:2666-5395