Phase composition, mechanical and thermal properties of (MgO)0.1-x(YO1.5)x(ZrO2)0.9 and (MgO)0.1-x(CaO)x(ZrO2)0.9 ceramics

(MgO)(0.1-x)(YO1.5)(x)(ZrO2)(0.9) (MYZ) and (MgO)(0.1-x)(CaO)(x)(ZrO2)(0.9) (MCZ) ceramics were prepared and their phase composition, bulk density, flexural strength, and thermal shock resistance were characterized. There was an abrupt change of c/(c+m) from 29% to 75% as 0<x<0.01 for MYZ, and a change of c/(c+m) from 42% to 88% appeared as 0.02<x<0.03 for MCZ (the c and m representing the content of the cubic and the monoclinic phases respectively). When x=0.01 similar to 0.05, the resulting MYZ specimens had the resembling c/(c+m) at about 75%, and a thermal shock resistance of more than 5 times (1100 degrees C double left right arrow 25 degrees C) appeared for x=0.03 similar to 0.05 specimens. However for MCZ, only specimen of x=0.01 with c/(c+m) of 33% had a thermal shock resistance more than 5 times.