Introduction of lanthanum oxide into an aluminum-zirconium matrix leads to the formation of LaAl11O18 during sintering in air at 1520°C for 2 h. The grain size of aluminum oxide is at the level of 0.75 μm. The highest crack resistance (6.2 ± 0.3 MPa·m1/2) with the selected technological parameters for obtaining the materials is found for the material with 3 wt.% LaAl11O18. The critical stress intensity coefficient of such material is 24% higher than that of aluminum-zirconium ceramics without additives. [ABSTRACT FROM AUTHOR]