Study of deformation mechanisms in flash-sintered yttria-stabilized zirconia by in-situ micromechanical testing at elevated temperatures

• Main Authors: Jaehun Cho, Jin Li, Han Wang, Qiang Li, Zhe Fan, A.K. Mukherjee, W. Rheinheimer, Haiyan Wang, X. Zhang
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2019-05-01
• Series: Materials Research Letters
• Subjects: Flash sintering; deformation mechanism; in-situ microcompression test; dislocation
• Online Access: http://dx.doi.org/10.1080/21663831.2019.1575924

Flash sintering has received wide attention lately due to its ultrafast densification process at low sintering temperature. However, the deformability of flash-sintered ceramics remains poorly understood. Yttria-stabilized zirconia (YSZ) was processed by flash sintering to study deformation mechanism. Transmission electron microscopy studies show that the flash-sintered YSZ contains ultrafine grains and dislocations. Strain rate jump tests at elevated temperature by in-situ microcompression indicate the existence of a large threshold stress. The activation energy of deformation is ∼145 kJ/mol, similar to the activation energy for oxygen vacancy migration. The deformation mechanisms of the flash-sintered YSZ at elevated temperatures are discussed.