TY - GEN
T1 - Post-spray treatment of plasma sprayed yttria stabilized zirconia (YSZ) electrolyte with spark plasma sintering (SPS) technique
AU - Khor, K. A.
AU - Chen, X. J.
AU - Chan, S. H.
PY - 2004
Y1 - 2004
N2 - Spark-plasma sintering (SPS) was adopted in this study as a rapid post-spray treatment for yttria stabilized zirconia (YSZ) electrolytes prepared through the direct current (dc) plasma spray process. The lamellar microstructure in the as-sprayed samples was found to significantly reduced the ionic conductivity of the YSZ electrolytes. However, the ionic conductivity (at 1053°C) increased sharply from 0.065 S/cm for the as-sprayed electrolyte to 0.122 S/cm for electrolyte post-spray treated through SPS at 1400°C for 3 minutes. These phenomena were attributed to the microstructure transformation from lamellar structure of the as-sprayed samples to equi-axial type granular structure of the post-spray samples treated by SPS. Correspondingly, porosity reduced from ∼ 10.72 % in as-sprayed coating to ∼ 1.38% in the SPS sample treated at 1400°C for 3 min. Majority of the pores in the SPS sample were also found to have contracted to a narrow size range 0.03 - 1 μm. AC impedance spectroscopy demonstrated the effect of the microstructure modification between samples treated in the SPS at temperature 1200, 1300 and 1400°C for 3 minutes with the concomitant reduction of the resistivity, which is consistent with the microstructure changes of the YSZ electrolyte from lamellar structure to granular structure. Overall, the results show that spark-plasma-sintering (SPS) is an effective and rapid post-spray treatment to improve the relative density and electrical properties of plasma sprayed YSZ electrolytes.
AB - Spark-plasma sintering (SPS) was adopted in this study as a rapid post-spray treatment for yttria stabilized zirconia (YSZ) electrolytes prepared through the direct current (dc) plasma spray process. The lamellar microstructure in the as-sprayed samples was found to significantly reduced the ionic conductivity of the YSZ electrolytes. However, the ionic conductivity (at 1053°C) increased sharply from 0.065 S/cm for the as-sprayed electrolyte to 0.122 S/cm for electrolyte post-spray treated through SPS at 1400°C for 3 minutes. These phenomena were attributed to the microstructure transformation from lamellar structure of the as-sprayed samples to equi-axial type granular structure of the post-spray samples treated by SPS. Correspondingly, porosity reduced from ∼ 10.72 % in as-sprayed coating to ∼ 1.38% in the SPS sample treated at 1400°C for 3 min. Majority of the pores in the SPS sample were also found to have contracted to a narrow size range 0.03 - 1 μm. AC impedance spectroscopy demonstrated the effect of the microstructure modification between samples treated in the SPS at temperature 1200, 1300 and 1400°C for 3 minutes with the concomitant reduction of the resistivity, which is consistent with the microstructure changes of the YSZ electrolyte from lamellar structure to granular structure. Overall, the results show that spark-plasma-sintering (SPS) is an effective and rapid post-spray treatment to improve the relative density and electrical properties of plasma sprayed YSZ electrolytes.
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M3 - Conference contribution
AN - SCOPUS:10444267343
SN - 0871708094
T3 - Proceedings of the International Thermal Spray Conference
SP - 27
EP - 31
BT - Proceedings of the International Thermal Spray Conference
T2 - Proceedings of the International Thermal Spray Conference
Y2 - 10 May 2004 through 12 May 2004
ER -