TY - JOUR
T1 - Creep behavior of perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1-xZrxO3-δ
AU - Stournari, V.
AU - ten Donkelaar, S.F.P.
AU - Malzbender, J.
AU - Beck, T.
AU - Singheiser, L.
AU - Bouwmeester, H.J.M.
N1 - Funding Information:
Financial support from the Helmholtz Association of German Research Centers (Initiative and Networking Fund) through the Portfolio-topic MEM-BRAIN is gratefully acknowledged. The authors express their gratitude to Ms. T. Osipova, Mr. R. Küppers and Mr. J. Mönch for technical assistance, to Dr. E. Wessel and Dr. D. Grüner for SEM analysis, and to Mr. M. Ziegner for XRD analysis. Finally, Dr. G. Pećanac is gratefully acknowledged for fruitful discussions.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Compressive creep tests have been performed on perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1-xZrxO3-δ (BSCF-Z100·x), where x=0.01, 0.03, 0.05 and 0.1, for the use as oxygen transport membrane, in air at 800-950°C and at nominal stresses of 30MPa and 63MPa. X-ray diffraction and microstructural observations support a solid solubility limit of ZrO2 between 0.033 secondary phases in grain boundaries at compositions beyond this limit. Zr substitution of (Co,Fe) in BSCF is found to suppress grain growth significantly, which is attributed to a solute and/or particle drag (Zener pinning) mechanism. Observed activation energies and stress exponents point to diffusional creep as the predominant mechanism for creep in BSCF-Z100·x ceramics, at T≥850°C. This is further supported by the fact that the grain-size-normalized steady-state creep rate varies little for the different BSCF-Z100·x compositions. It was confirmed that Zr substitution does not significantly affect the thermal hysteresis of the creep behavior as observed for pure BSCF.
AB - Compressive creep tests have been performed on perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1-xZrxO3-δ (BSCF-Z100·x), where x=0.01, 0.03, 0.05 and 0.1, for the use as oxygen transport membrane, in air at 800-950°C and at nominal stresses of 30MPa and 63MPa. X-ray diffraction and microstructural observations support a solid solubility limit of ZrO2 between 0.033 secondary phases in grain boundaries at compositions beyond this limit. Zr substitution of (Co,Fe) in BSCF is found to suppress grain growth significantly, which is attributed to a solute and/or particle drag (Zener pinning) mechanism. Observed activation energies and stress exponents point to diffusional creep as the predominant mechanism for creep in BSCF-Z100·x ceramics, at T≥850°C. This is further supported by the fact that the grain-size-normalized steady-state creep rate varies little for the different BSCF-Z100·x compositions. It was confirmed that Zr substitution does not significantly affect the thermal hysteresis of the creep behavior as observed for pure BSCF.
KW - BSCF
KW - Creep
KW - Oxygen transport membrane
KW - Perovskite
KW - Zr substitution
KW - 2023 OA procedure
UR - http://www.scopus.com/inward/record.url?scp=84922165475&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2015.01.005
DO - 10.1016/j.jeurceramsoc.2015.01.005
M3 - Article
SN - 0955-2219
VL - 35
SP - 1841
EP - 1846
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 6
ER -