Mechanical behavior of La0.8Sr0.2Ga0.8Mg0.2O3 perovskites
Abbreviated Journal Title
Ceram. Int.
Keywords
Fracture; Mechanical properties; Perovskites; Fuel cells; Slow crack; growth; DOPED LANTHANUM GALLATE; OXIDE FUEL-CELLS; ION CONDUCTOR; TEMPERATURE; ELECTROLYTE; LAGAO3; ALUMINA; CRACK; Materials Science, Ceramics
Abstract
This paper examines the important mechanical properties of commercially purchased La0.8Sr0.2Ga0.8Mg0.2O3 at room temperature and 800 degrees C. Sr and Mg-doped lanthanum gallates (LSGM) are strong candidates for use as solid electrolytes in lower temperature solid oxide fuel cells operating at or below 800 degrees C. The material was found to be phase pure with a Young's modulus value of similar to 175 GPa. The four point bending strength of the LSGM samples remained almost constant from 121 +/- 35 MPa at room temperature to 126 +/- 20 MPa at 800 degrees C. The fracture toughness, as measured by the single edge V notch beam (SEVNB) method, was 1.22 +/- 0.06 MPa root m at room temperature, 1.04 +/- 0.09 MPa root m at 700 degrees C followed by a small increase 1.31 +/- 0.16 MPa root m at 800 degrees C. We also report, for the first time, the static subcritical (or slow) crack-growth (SCG) behavior of natural cracks in LSGM performed in four point bending tests at room temperature. The exponent of a power-law representation in the SCG tests was found to be n = 15, a rather low value showing LSGM to be highly susceptible to room temperature SCG. (C) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Journal Title
Ceramics International
Volume
35
Issue/Number
3
Publication Date
1-1-2009
Document Type
Article
Language
English
First Page
1235
Last Page
1241
WOS Identifier
ISSN
0272-8842
Recommended Citation
"Mechanical behavior of La0.8Sr0.2Ga0.8Mg0.2O3 perovskites" (2009). Faculty Bibliography 2000s. 1990.
https://stars.library.ucf.edu/facultybib2000/1990
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