Effects of ceramic layer height on the mechanical properties of Cf/SiC ceramic matrix composites fabricated by fiber-laying-assisted material extrusion 3D printing

Tradition fabrication methods of continuous carbon fiber reinforced SiC ceramic matrix composites (Cf/SiC CMCs) cannot meet the requirements of complex structures. In this research, Cf/SiC CMCs were fabricated through a novel technology combined with fiber-laying-assisted material extrusion (ME) 3D printing with precursor infiltration and pyrolysis (PIP). The ME system was utilized to produce SiC slurry, while the fiber-laying system was employed to embed continuous carbon fibers, resulting in the integrated fabrication of Cf/SiC CMC green bodies. Then Cf/SiC CMCs underwent the PIP process to achieve densification. The impact of ceramic layer height on the microstructure and mechanical performance of 3D-printed Cf/SiC CMCs was thoroughly examined. The gaps between continuous carbon fibers and SiC ceramic matrix could be reduced by lowering the ceramic layer height. The obtained Cf/SiC CMCs showed delayed fracture behaviors. As the ceramic layer height increased, both the bending strength and fracture toughness initially improved before declining. High performance Cf/SiC CMCs with a bending strength of 288.49 MPa and a fracture toughness of 15.19 MPa m1/2 were simultaneously obtained when the ceramic layer height was 0.75 mm. This work can provide novel insights into the 3D printing of fiber reinforced ceramic matrix composites. [Display omitted] •Continuous carbon fiber reinforced SiC ceramic matrix composites were prepared by fiber-laying-assisted material extrusion combined with precursor infiltration and pyrolysis.•The effect of ceramic layer height on the microstructure and mechanical properties were investigated.•The maximum bending strength and fracture toughness reached 288.49 MPa and 15.19 MPa m1/2, respectively.