Toughening of ZrB2–SiC ceramics with the microstructure ZrB2/Zr–Al–C fibrous monolith

A ZrB2–20 vol.% SiC–30 vol.% Zr–Al–C ceramic was fabricated by hot pressing at 1900 °C and 30 MPa for 1 h in vacuum. The ZrB2–SiC/Zr–Al–C ceramic showed an excellent fracture toughness of 5.4 ± 0.4 MPa m1/2 due to its ZrB2/Zr–Al–C fibrous monolith microstructure and the in situ formed layered Zr–Al–C grains, which could enhance crack deflection, crack bridging and crack branching. In addition, the weaker interface bonding and weaker internal layers existed within the Zr–Al–C crystal.