Synthesis and Study of Composite Materials in the ZrO2(Y2O3)–MgAl2O4 System

Resumo

Powders–precursors of a tetragonal solid solution based on partially stabilized zirconium dioxide (t-ZrO₂) and aluminum-magnesium spinel (MgAl₂O₄) are synthesized using the method of the cocrystallization of solutions of nitrate salts from which nanocrystalline (<100 nm) composite materials are fabricated at 1400°C in the ZrO₂(Y₂O₃)–MgAl₂O₄ system with an open porosity of 3%. The structure, physical–mechanical properties, and thermal stability of the nanocomposites are investigated. It is established that the introduction of MgAl₂O₄ into the matrix of the solid t-ZrO₂ solution increases the thermal resistance of the ceramics under the thermal cycling conditions (20–1000°С). The effect of thermal cycling on the phase composition, hardness, and bending strength of the ceramics in the ZrO₂(Y₂O₃)–MgAl₂O₄ system is investigated.