ALUMINUM TITANATE TETRAGONAL ZIRCONIA COMPOSITE WITH LOW THERMAL-EXPANSION AND HIGH-STRENGTH SIMULTANEOUSLY

Aluminium titanate was strengthened by alloying with 3 mol% yttria sta bilized zirconia to attain a small expansion coefficient of 2 x 10(-6) and a high strength of 100 MPa, simultaneously. Long milling and opti mization of the composition of the alloy to an equal weight of the com ponent oxides and also of the firing temperature at 1400 degrees C wer e important for the purpose. In the optimal conditions, aluminum titan ate grains of 3 mu m was surrounded by zirconia matrix of ca. 0.3 mu m grains containing zirconium titanate where would be a balance between the tension in the matrix and the expansion force of aluminum titanat e grains. Formation of zirconium titanate was important for the streng thening to decrease the lowering of the strength brought about by the unstabilization of PSZ.