Microstructure and mechanical properties of Al2O3/ZrO2 eutectic ceramic composites prepared by explosion synthesis

Al2O3/ZrO2 eutectic ceramics were prepared by explosion synthesis using Al and Zr(NO3)4 as raw materials. The Al2O3/ZrO2 eutectic microstructure showed that the rod-like ZrO2 phases with a diameter 200 nm were embedded orderly in Al2O3 matrix. With the increasing of the reaction temperature, the volume content of the Al2O3/ZrO2 eutectic increased accordingly, and the diameter and phase spacing of the rod-like ZrO2 decreased, which was mainly attributed to the sufficient diffusion at higher temperature and the large degree of supercooling. Due to the fine microstructure of the Al2O3/ZrO2 eutectic, the Vickers hardness and fracture toughness can reach 17.7 GPa and 10.3 MPa m1/2, respectively.

► Al2O3–ZrO2 eutectic composites were prepared by explosion synthesis.
► High reaction temperature was benefit to improve the volume content and fine microstructure of the eutectic.
► The Vickers hardness and fracture toughness can reach 17.7 GPa and 10.3 MPa m1/2, respectively.