Direct ink writing of chopped carbon fibers reinforced polymer-derived SiC composites with low shrinkage and high strength.

The chopped carbon fiber reinforced SiC (C f /SiC) composite has been regarded as one of the excellent high-temperature structural materials for applications in aerospace and military fields. This paper presented a novel printing strategy using direct ink writing (DIW) of chopped fibers reinforced polymer-derived ceramics (PDCs) with polymer infiltration and pyrolysis (PIP) process for the fabrication of C f /SiC composites with high strength and low shrinkage. Five types of PDCs printing inks with different C f contents were prepared, their rheological properties and alignment of carbon fiber in the printing filament were studied. The 3D scaffold structures and bending test samples of C f /SiC composites were fabricated with different C f contents. The results found that the C f /SiC composite with 30 wt% C f content has high bending strength (∼ 7.09 MPa) and negligible linear shrinkage (∼ 0.48%). After the PIP process, the defects on the C f /SiC composite structures were sufficiently filled, and the bending strength of C f /SiC composite can reach up to about 100 MPa, which was about 30 times greater than that of the pure SiC matrix without C f. This work demonstrated that the printed C f /SiC composites by using this method is beneficial to the development of the precision and complex high-temperature structural members. • The chopped fibers reinforced direct ink writing with PIP processing was proposed. • The carbon fibers reinforced polymer-derived SiC composites were prepared. • The C f /SiC composite with 30 wt% fiber has excellent linear shrinkage (< 0.5%). • The reinforced C f /SiC composite has satisfactory bending strength (∼ 103.14 MPa). [ABSTRACT FROM AUTHOR]