An investigation on the electromagnetic wave absorbing performance and corrosion resistance of carbonyl iron powder/epoxy coatings modified by ferrosoferric oxide and basalt fibers.

With the development of science and technology, there is a great demand for electromagnetic wave absorbing materials for both military and civilian purposes. Among them, carbonyl iron powder (CIP) has attracted a lot of attention due to its mature production system and good electromagnetic wave loss capability. However, the application of CIP is limited due to poor impedance matching, poor corrosion resistance, and poor oxidation resistance. Based on this, in this work, CIP and basalt fibers (BF) were used and flower-like ferrosoferric oxide (Fe₃O₄) was generated in situ on their surfaces by hydrothermal method. The results showed that the generation of Fe₃O₄ with the addition of BF greatly optimized the impedance matching of the CIP. The modified CIP had a minimum reflection loss of -51.09 GHz, corresponding to an effective absorption bandwidth (<-10 dB) of 6.16 GHz, fully covering the Ku-band with just a 1.5 mm coating thickness. Thanks to the protective effect of Fe₃O₄, the oxidation weight gain temperature of the modified CIP powder in air was increased from 240 °C to 500 °C, showing good thermal stability and oxidation resistance. In addition, the corrosion resistance of the coating was tested and analyzed using electrochemical impedance spectroscopy (EIS). The results showed that the impedance modulus of the coating at 0.01 Hz was enhanced by one order of magnitude from 10⁶ Ω·cm² to 10⁷ Ω·cm². Finally, the radar cross section (RCS) of the material was simulated using CTS software to further evaluate the wave absorption properties.