Additive Manufacturing of C/C-SiC Ceramic Matrix Composites by Automated Fiber Placement of Continuous Fiber Tow in Polymer with Pyrolysis and Reactive Silicon Melt Infiltration

An additive manufacturing process for fabricating ceramic matrix composites has been developed based on the C/C-SiC system. Automated fiber placement of the continuous carbon fibers in a polyether ether ketone matrix was performed to consolidate the carbon fibers into a printed preform. Pyrolysis was performed to convert the polymer matrix to porous carbon, and then Si was introduced by reactive melt infiltration to convert a portion of the carbon matrix to silicon carbide. The densities and microstructures were characterized after each step during the processing, and the mechanical properties were measured. The C/C-SiC composites exhibited a porosity of 10-20%, characteristic flexural strength of 234.91 MPa, and Weibull modulus of 3.21. The composites displayed toughness via a significant displacement to failure.

Automated summary

An additive manufacturing process based on the C/C-SiC system has been developed for fabricating ceramic matrix composites. Continuous carbon fibers were consolidated into a printed preform using automated fiber placement and polyether ether ketone matrix. Pyrolysis and reactive melt infiltration were employed to convert the polymer matrix to porous carbon and introduce silicon to form silicon carbide. The resulting C/C-SiC composites exhibited good mechanical properties, including high flexural strength, toughness, and porosity.