Creep behavior of perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1−xZrxO3−δ
| Autor: | Tilmann Beck, Vasiliki Stournari, Lorenz Singheiser, Jürgen Malzbender, Henricus J.M. Bouwmeester, S.F.P. ten Donkelaar |
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| Přispěvatelé: | Inorganic Membranes |
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Zener pinning Oxygen transport Thermodynamics Zr substitution Creep BSCF Perovskite Stress (mechanics) Grain growth visual_art Oxygen transport membrane 2023 OA procedure Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Grain boundary Ceramic Perovskite (structure) |
| Zdroj: | Journal of the European Ceramic Society, 35(6), 1841-1846. Elsevier |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2015.01.005 |
| Popis: | 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 30 MPa and 63 MPa. X-ray diffraction and microstructural observations support a solid solubility limit of ZrO2 between 0.03 < x < 0.05. Evidence is found for the formation of (Ba,Sr)ZrO3 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. |
| Databáze: | OpenAIRE |
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