Study on absorption and mechanical performance of 3D-printed MWCNT/Fe₃O₄/PA6 composites

The investigation of microwave absorption materials represents a significant area of research in military stealth applications. Carbon-based materials have garnered extensive attention owing to their superior dielectric loss properties. However, their reliance on a single loss mechanism restricts further enhancement of absorption performance. To address this limitation, this study employed fused deposition modeling (FDM) 3D printing technology to fabricate Fe 3 O 4 /MWCNT/PA6 composite microwave-absorbing materials. The effects of varying Fe 3 O 4 content on the electromagnetic absorption capabilities and mechanical properties of the composites were systematically examined. The findings reveal that increasing the Fe 3 O 4 content significantly broadens the effective absorption bandwidth of the composites and concurrently improves their tensile properties. Specifically, when the Fe 3 O 4 content is 20%, the composite exhibits optimal performance at a thickness of 1.0 mm, achieving an effective absorption bandwidth of 4.08 GHz (13.52–17.6 GHz) and a reflection loss peak of -46.83 dB. Additionally, the tensile strength reaches 54.2 MPa, demonstrating that the composite achieves enhanced absorption performance at low thickness without compromising mechanical integrity.