Multiscale toughening of ZrB2-SiC-Graphene@ZrB2-SiC dual composite ceramics

The design of bioinspired architectures is effective for increasing the toughness of ceramic materials. Particularly, a dual composite equiaxial architecture is ideal for fabricating weak interface-toughened ZrB 2 -SiC ceramics with isotropic performance. In this paper, ZrB 2 -SiC-Graphene@ZrB 2 -SiC dual composite ceramics were synthesized via an innovative processing technique of granulating-coating method. ZrB 2 -20 vol.% SiC containing 30 vol.% Graphene was selected as weak interface to realize multiscale toughening and improve the thermal shock resistance of ZrB 2 -SiC ceramic materials. The incorporation of ZrB 2 -SiC-Graphene weak interface into the ZrB 2 -SiC matrix improved the damage tolerance and critical thermal shock temperature difference. The design of equiaxial structures moderated the anisotropy of performance in different planes. The graphene sheets incorporated in the ZrB 2 -SiC-Graphene interface phase played a key role in multiscale toughening, including macroscopic toughening of crack deflection and microcracks, and microscopic toughening of graphene bridging and pull-out.