Elemental, Thermal, and Structural Characterization of ZnO Doped 8 mol% Yttria-Stabilized Zirconia (8YSZ) Ceramics

2017 ◽  
Vol 888 ◽  
pp. 57-61 ◽  
Author(s):  
Johar Banjuraizah ◽  
Tinesha Selvaraj ◽  
Zainal Arifin Ahmad

8 mol% of Yttrium oxide doped Zirconia (8YSZ) is one of the most explored compositions which give high ionic conductivities and good power output at 1000 °C. Generally, dopant was added to improve the sinterability of 8YSZ ceramics. In this present study, granulated 8YSZ powders with multimodal size was mixed with ZnO (0,1,2,3 wt%) using mortar and pestle. The mixed powder was compacted and sintered at 1550°C for 2 hours. 2 distinct endothermic peaks were observed in DTA plot of all samples. However, samples contain high amount of ZnO had a broader endothermic peak which resulted from the melting of ZnO. Rietveld refinement results indicate that the tetragonal phase appeared as the dominant phase for all doped and undoped samples, while cubic and monoclinic phase as the secondary phase. The monoclinic phase decreased as the amount of ZnO increased.

Author(s):  
J. Ilavsky ◽  
J. Wallace ◽  
J.K. Stalick

Abstract Phase stability of the thermal barrier deposits made from yttria-partially-stabilized zirconia (Y-PSZ) is a requirement for extended service lifetime. The response of Y-PSZ plasma-sprayed deposits to annealing at 1000 °C, 1200 °C, and 1400 °C with times from 1 to 1000 hours has been evaluated using Rietveld analysis of neutron diffraction data. Results show that yttria concentration of the as-sprayed tetragonal zirconia component generally decreased with increasing annealing temperature and time. As the yttria content in the tetragonal phase approached a limiting concentration, the tetragonal phase transformed into monoclinic phase on cooling. An increase in monoclinic phase content was clearly observable after annealing 24 hours at 1400 °C and was nearly 35 % after 100 hours at 1400 °C. A similar trend was observed at 1200 °C for longer annealing times, with monoclinic phase formation beginning after 400 hours. At 1000 °C experimental times were not sufficient for monoclinic phase to form although a decrease in the yttria concentration in the tetragonal phase was observed. Keywords: neutron scattering, yttria-stabilized zirconia, phase composition, Rietveld analysis


Author(s):  
Juan Luis Pantoja-Pertegal ◽  
Antonio Díaz-Parralejo ◽  
Antonio Macías-García ◽  
J.Sánchez González ◽  
Eduardo M. Cuerda-Correa

1997 ◽  
Vol 56 (10) ◽  
pp. 5856-5865 ◽  
Author(s):  
B. Savoini ◽  
J. E. Muñoz Santiuste ◽  
R. González

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