Optimal sintering temperature for Ce0.9Gd0.1O2−δ–La0.6Sr0.4Co0.2Fe0.8O3–δ composites evaluated through their microstructural, mechanical and elastic properties

Abstract In this paper, we report on the selection of an optimal sintering temperature for Ce 0.9 Gd 0.1 O 2−δ –La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ composites through characterization of their microstructural, mechanical, and elastic properties. For this selection, sintering was performed mainly at three different temperatures—1100, 1250, and 1400 °C—for 3 h. The samples were systematically investigated in terms of their relative density, microstructure, flexural strength, hardness, elastic modulus, and Poisson's ratio. An increase in density with an increase in sintering temperature was observed to cause a significant improvement in the flexural strength, hardness, and elastic modulus. However, an excessively high temperature (>1250 °C) was detrimental to the flexural strength and hardness because of the occurrence of grain growth. The optimal sintering temperature was identified to be 1250 °C from an analysis of samples with superior mechanical properties and adequate elastic properties. The optimal flexural strength and hardness were found to be 211 ± 21 MPa and 9.34 ± 0.5 GPa, respectively, at room temperature.