Strength characterization of tubular ceramic materials by flexure of semi-cylindrical specimens

Mechanical strength at elevated temperatures and operating atmospheres needs to be characterized during development of tubular ceramic components for advanced energy technologies. Typical procedures are time-consuming because a large number of tests are required for a reliable statistical strength characterization and every specimen has to be subjected to the process conditions individually. This paper presents an efficient strength characterization methodology for tubular ceramics. The methodology employs flexure of semi-cylindrical specimens as the strength test and implements the tests within a facility capable of loading multiple specimens in controlled environments. The stress field is analyzed in detail with finite element analyses. The validity of the test is found to depend on specimen dimensions and the valid range is established. The methodology is demonstrated by experimental measurements conducted on oxygen transport membrane materials at room temperature and 850 °C.