Absorption properties of twinned SiC nanowires reinforced Si3N4 composites fabricated by 3d-prining

• The combination of 3DP and PIP was first employed to fabricate Si3N4–SiC in this work.
• Twinned SiC nanowires were formed in the porous Si3N4 using PIP.
• We report a novel Si3N4–SiC ceramic that has superior absorption properties than already-reported PDCs.

Near net- and complex shaped porous silicon nitride (Si3N4) composites reinforced with in-situ formed twinned silicon carbide (SiC) nanowires (NWs) were successfully fabricated by 3d-printing (3DP) followed by polymer precursor infiltration and pyrolysis (PIP) up to 1400 °C. An increase of the PIP cycle number of the printed bodies resulted in a homogeneous distribution of SiC NWs in the fabricated composites. An increase of SiC NW content in the fabricated composites led to the growth of both the real and the imaginary parts of permittivity. The formation of twinned SiC NWs with high electrical conductivity led to a minimal electromagnetic wave RC of −57 dB, demonstrating that Si3N4–SiC ceramics with the in-situ formed SiC NWs have a superior microwave absorbing ability.