In-situ formation of Ti3SiC2 interphase in SiCf/SiC composites by molten salt synthesis

Titanium silicon carbide (Ti3SiC2) film was synthesized by molten salt synthesis route of titanium and silicon powder based on polymer-derived SiC fibre substrate. The pre-deposited pyrolytic carbon (PyC) coating on the fibre was utilized as the template and a reactant for Ti3SiC2 film. The morphology, microstructure and composition of the film product were characterized. Two Ti3SiC2 layers form the whole film, where the Ti3SiC2 grains have different features. The synthesis mechanism has been discussed from the thickness of PyC and the batching ratio of mixed powder respectively. Finally, the obtained Ti3SiC2 film was utilized as interphase to prepare the SiC fibre reinforced SiC matrix composites (SiCf/Ti3SiC2/SiC composites). The flexural strength (sigma(F)) and fracture toughness (K-IC) of the SiCf/Ti3SiC2/SiC composite is 460 +/- 20 MPa and 16.8 +/- 2.4 MPa center dot m(1/2) respectively.

Automated summary

A titanium silicon carbide (Ti3SiC2) film was successfully synthesized using a molten salt synthesis route on a polymer-derived SiC fiber substrate. The film consists of two layers of Ti3SiC2 with different grain features. The synthesis mechanism was discussed based on the thickness of the pre-deposited pyrolytic carbon (PyC) coating and the batching ratio of the mixed powder. The obtained Ti3SiC2 film was used as an interphase to prepare SiC fiber reinforced SiC matrix composites, which exhibited a flexural strength of 460 ± 20 MPa and a fracture toughness of 16.8 ± 2.4 MPa·m^(1/2).