Fabrication of 3D-SiC/aluminum alloy interpenetrating composites by DIW and pressureless infiltration

A novel method combining direct ink writing (DIW) and pressureless infiltration is proposed for fabricating 3D-SiC/Al composites. Chopped carbon fiber was added to DIW ink to serve as a pore-forming agent and facilitate pyrolysis to provide infiltration channels during the preoxidation process. The effects of SiC particle size and carbon fiber content on mechanical properties and the infiltration process were investigated. The thickness of the oxide films produced at different preoxidation temperatures was studied using a transmission electron microscope. The interfacial and interpenetrating phase compositions of 3D-SiC/Al were examined using scanning electron microscopy, an energy dispersive spectrometer, and X-ray diffraction. The results showed that carbon fiber can improve the infiltration effect, with SiO₂ layers of differing thickness affecting the infiltration process to different degrees. The final sample exhibited good mechanical properties with a bending strength of 330.3 MPa.