Anisotropic Microwave Absorption and Thermal Conductivity and Mechanical Performance of SiC / PDMS Composites Prepared via Direct Ink Writing Technology

ABSTRACT The rapid advancement of wireless communication technologies, integrated circuits, electric vehicles, has posed significant challenges in electromagnetic shielding and thermal management. In response, aligned silicon carbide/polydimethylsiloxane (SiC/PDMS) composites were fabricated via direct ink writing (DIW). The effects of SiC content and printing speed on the thermal conductivity of the composites were investigated. Additionally, the influence of SiC orientation on the microwave absorption (MA) and mechanical properties of the composites was investigated. The results show that the thermal conductivity and compression stress of the composites gradually increase as the SiC content rises, and the through‐plane thermal conductivity and the compression stress exceed that in the in‐plane direction. A maximum through‐plane thermal conductivity of 2.25 W m −1 K −1 was attained at a SiC content of 80 phr with a printing speed of 24 mm s −1 . Furthermore, the composite exhibits a superior MA performance at a SiC content of 60 phr, achieving a minimum reflection loss (RL min ) of −55.46 dB and a maximum effective absorption bandwidth (EAB max ) of 4.17 GHz. Overall, this research presents a rapid, efficient, and convenient strategy for fabricating high‐performance TIMs with tunable thermal and electromagnetic properties. Finite element analysis (FEA) further validates the effectiveness of the DIW process in achieving fiber alignment.