Evaluation of mechanical properties of tubular LSFCO perovskite membranes at elevated temperatures in reactive environments

This paper reports the mechanical properties of tubular membranes of mixed conducting La0.2Sr0.8Fe0.8Cr0.2O3-δ (LSFCO) perovskites at elevated temperatures. Strength, measured in a C-ring test over a temperature range of 22°–1000 °C in three different environments – air, 100% N2, and 90% CO2/10% CO mixtures – showed a decreasing behavior with increasing temperature and severity of reducing conditions. A maximum strength value of 340 MPa and a minimum of 105 MPa were observed at room temperature and at 1000 °C, respectively, in CO2/CO environment. Fractography was used to characterize the flaws and changes in fracture mode. Results indicate that the observed changes in strength and fracture morphology are associated with non-equilibrium segregation of elements when exposed to the reducing environment.