Influence of carbon nanotubes on the absorption performance and mechanical behavior of basalt fiber composite materials

Abstract Basalt fibers (BF) are widely used in shipbuilding due to their excellent corrosion resistance. However, basalt fibers do not possess good electromagnetic wave absorption properties, failing to meet the stealth performance requirements of ships. Therefore, this study focuses on basalt fiber composite materials, modifying the matrix by adding different amounts of carbon nanotubes (CNTs). Carbon nanotube‐basalt fiber‐epoxy resin absorptive composite materials are prepared using Vacuum Assisted Resin Transfer Molding (VARTM) technique to investigate the influence of CNT content on the materials. Samples with added CNTs can effectively absorb electromagnetic waves in the low‐frequency range, reducing surface reflectivity. In the high‐frequency range, the impedance matching value of the samples initially increases slowly. When the CNT content reaches 1.5 wt%, at a thickness of 2.5 mm and a frequency of 9.6 GHz, the minimum reflection loss of the sample is −14.40 dB, with an effective absorption bandwidth of 0.7 GHz. Also, CNTs can enhance the mechanical properties of composite materials. With increasing CNT content, both the bending strength and tensile strength of the composite materials are improved. When the CNT content reaches 1.5 wt%, the average tensile fracture strength of the material increases by 21%, and the bending strength increases by 9%. Highlights Enhanced low‐frequency electromagnetic wave absorption from CNTs and reduced polarization. Improved impedance matching and attenuation at high frequencies with CNTs. Significant enhancement in flexural and tensile strength due to CNTs and basalt fibers.