Microstructure and mechanical properties of zirconia-toughened ZrB2–MoSi2 composites prepared by hot-pressing

ZrO2-doped ZrB2–20 vol.% MoSi2 composites were prepared by hot-pressing. Compared with ZrB2–MoSi2 composite, the addition of ZrO2 caused an obvious improvement in microstructure as well as in mechanical properties. Due to the phase transformation toughening of ZrO2, the toughness of ZrB2–MoSi2 composites was clearly advanced by 50% from ∼4.3 to ∼6.3 MPa m1/2 regardless of the method of testing. Such enhancement, especially in toughness, indicates that it is an effective way to design ZrB2–MoSi2 composites with phase transformation toughening of ZrO2.