Thermal Tests and Their Effect on the Micro- and Macrostructure of Nanocrystalline ZrO₂

Abstract

The paper examines the effect of thermal tests in water cooling starting at 1000 ⁰C on structural and phase transformations in nanostructured ceramics based on ZrO₂ partially stabilized by Mg⁺² in high-temperature modifications. The ceramics have different amounts of magnesia in the ZrO₂–MgO solid solution and, as a consequence, different ratios of high- and low-temperature modifications of zirconia. It is shown that the ZrO₂–MgO solid solution decomposes regardless of its magnesia content with increasing number of thermal tests, but the ceramics remain resistant to thermal shock even in case of complete MgO removal, i.e., zirconia destabilization.