Characterization of flexible radar-absorbing materials based on ferromagnetic nickel micron-fibers

Flexible radar-absorbing materials have great application significance in stealth technology. In this paper, a novel radar-absorbing material based on ferromagnetic nickel micron-fibers with 38–40 mm length and 10–12 µm diameter was successfully prepared through bundle-fiber drawing and electrochemical treatment. The characterization of morphology, chemical composition, magnetic and mechanical properties, including tensile strength, bending rigidity and friction, of the prepared ferromagnetic nickel micron-fiber is investigated. The results showed that compared with conventional radar absorbers, ferromagnetic nickel micron-fibers have many advantages in their appearance and magnetic performance. The total ferromagnetic metal fraction of Ni and Fe was above 90%. Irregular cross-section and large aspect ratio of 3800 of the fiber enabled the magnetic hysteresis loss and absorbing performance to be increased obviously. Its saturation magnetization Ms was 116 emu/g with coercivity Hc of 5.8 × 10 ³ A/m, initial permeability of 2036 H/m and Curie temperature of 996 K, confirming the fiber performed a relatively strong magnetic absorbing effect and high temperature stability. The tensile and friction properties of ferromagnetic nickel micron-fiber were also analyzed to evaluate the spinnability.