The mechanical behavior of lanthanum cobaltite-based perovskites with a mixed ion-electron conductivity at different temperatures

The mechanical behavior of a perovskite-type ceramic based on partially substituted lanthanum cobaltites is studied over a wide temperature range. The La0.8Ca0.2CoO3 composite is shown to be the most inelastically deformable, high-strength, and crack-resistant. In perovskites, the brittleness can be considered as a measure of both inelasticity and ferroelasticity. The perovskites are tested for deformability using bending and indentation techniques, and an analogy in the results obtained by the two techniques is noted. Specific features of the fracture of perovskites tested by the Vickers indentation method are discussed. The crack resistance and stress-strain diagrams of the La0.8Ca0.2CoO3 composite are studied as a function of temperature. Fractographic test data are used to analyze the results obtained.