Electromagnetic wave absorption properties of flaky Fe–Ti–Si–Al nanocrystalline composites

Nanocrystalline Fe–Ti–Si–Al flaky powders with large aspect ratio have been fabricated by high-energy planetary milling melt-spun ribbons. Magnetic composites made of thermally annealed Fe–Ti–Si–Al flaky powders embedded in epoxy resin exhibit excellent electromagnetic wave absorption properties in a wide frequency range from 100 MHz to 2.65 GHz. Ti additions can enhance the electrical resistivity of Fe–Si–Al alloy without changing the crystallographic structure, resulting in the reduction of eddy current loss at high frequencies. Moreover, the substitution of Ti for Fe enhances the cut-off frequency of flaky powder–polymer composites. Meanwhile, compared to the Ti-free composites, reflection loss of the Ti-doped composites (3 mm in thickness) is lower than −10 dB in the frequency range from 593 MHz to 1.83 GHz, indicating that the composites can effectively work in a wider frequency bandwidth.