The mechanical enhancement mechanism in additively manufactured continuous SiC_f/SiC ceramic matrix composites

Developing lightweight and high-strength materials capable of enduring harsh environments is of interest in various aerospace and defense systems. Despite recent success in exploiting continuous fiber-reinforced silicon carbide (SiC) ceramic matrix composites (CMCs) with high-temperature resistance, it remains challenging to achieve high geometric complexity with exceptional mechanical properties. Here, we report a novel hybrid fabrication strategy integrating additive manufacturing and multiple precursor infiltration pyrolysis (PIP) processes for fabricating three-dimensional SiC CMCs. The pyrolytic carbon generated by polymer carbonization acts as the interface layer of the SiC CMCs, allowing for small slips, which not only transfer load but also avoid brittle fracture. After twelve cycles of polycarbosilane (PCS) PIP processes, the specimen exhibits a peak flexural strength of 340 MPa, and its highest fracture toughness was measured at 11.27 MPa·m^1/2. Our findings provide novel perspectives for the development of SiC CMCs, enabling broad applications. © 2025 Elsevier Ltd.