Microstructure and mechanical properties of PDA-CNTs@f-Ti3C2-reinforced SiC matrix composites

Poor fracture toughness is a major limitation of SiC ceramics, which greatly affects their application range. Herein, a novel strategy is proposed to enhance the fracture toughness of SiC ceramics by cross-linking carbon nanotubes (CNTs) coated with polydopamine (PDA) to Ti 3 C 2 modified with 3-glycidyloxypropyltrime-thoxysilane (KH560) (PDA-CNTs@f-Ti 3 C 2 ). Then, PDA-CNTs@f-Ti 3 C 2 was added to SiC powder to prepare the final composite. The influence of PDA-CNTs@f-Ti 3 C 2 addition on the microstructure and mechanical properties of the SiC composite is discussed. The results showed that, compared with CNTs and Ti 3 C 2 , the PDA-CNTs@f-Ti 3 C 2 composites exhibited better dispersibility in water. The flexural strength was significantly enhanced (~89%) in the SiC composite containing 3 wt% PDA-CNTs@f-Ti 3 C 2 , from 228.99 MPa to 433.55 MPa. The fracture toughness of the SiC composite containing 3 wt% PDA-CNTs@f-Ti 3 C 2 improved by 62%, from 3.97 MPa/m 1/2 to 6.44 MPa/m 1/2 .