Title

Mechanical Behavior Of La0.8Sr0.2Ga0.8Mg0.2O3 Perovskites

Keywords

C. Fracture; C. Mechanical properties; D. Perovskites; E. Fuel cells; Slow crack growth

Abstract

This paper examines the important mechanical properties of commercially purchased La0.8Sr0.2Ga0.8Mg0.2O3 at room temperature and 800 °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 °C. The material was found to be phase pure with a Young's modulus value of ∼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 °C. The fracture toughness, as measured by the single edge V notch beam (SEVNB) method, was 1.22 ± 0.06 MPa√m at room temperature, 1.04 ± 0.09 MPa√m at 700 °C followed by a small increase 1.31 ± 0.16 MPa√m at 800 °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. © 2008 Elsevier Ltd and Techna Group S.r.l.

Publication Date

4-1-2009

Publication Title

Ceramics International

Volume

35

Issue

3

Number of Pages

1235-1241

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.ceramint.2008.06.013

Socpus ID

59349116759 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/59349116759

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