Co-authors​ :

 Itziar SERRANO-MUNOZ (GERMANY), Mossaab MOUIYA (FRANCE), Andreas KUPSCH (GERMANY), Marko PRASEK (ITALY), Giovanni BRUNO (GERMANY) 

The stress–strain behavior of ceramics, such as aluminum titanate (AT), has certain features that are unusual for brittle materials—in particular, a substantial nonlinearity under uniaxial tension, and load–unload hysteresis caused by the sharp increase of the incremental stiffness at the beginning of unloading. These features are observed experimentally and are attributed to microcracking. We use advanced mechanical testing to observe the mechanical response at room and high temperature; electron microscopy, and X-ray refraction radiography to observe the microstructural changes. Specifically, X-ray refraction radiography is combined with in-situ heating at high-temperatures (up to 1400°C) to be able to monitor the relative closure of microcracks as a function of increasing temperature, for the case two AT materials possessing different grain sizes.