Effect of corrosion performance of FeSiAl electromagnetic shielding coating on absorbing properties

As science and high-tech have developed, stealth technology has gained increasing prominence in the military field. Application of stealth technology can improve the survival, defense, and attack capabilities of military equipment, thus it has become a focus in the field of modern military science. As the core part of radar stealth technology, absorbing materials are widely required by various industries. For military equipment such as ships operating in the marine environment, absorptive coating can not only make the military equipment effectively invisible, but can also enhance the corrosion protection capability of the equipment itself. Once the surface of an absorptive coating is corroded, not only will its corrosion resistance become compromised, but its absorbing performance may also be affected, leading to threats and hidden dangers to the safety of the weapons and equipment. At present, most researchers are paying more attention to the effect of absorbent particles on absorbing properties during studies of absorptive coatings. However, after addition of absorbent particles, the effect of the absorptive coating on a material's absorbing properties is unknown when corrosion resistance is constantly changing. Therefore, research in this area is of great significance in selection of surface absorbing coatings for marine weapons and equipment. In this study, FeSiAl electromagnetic shielding coating, based on Q235 cold-rolled steel, was used as the experimental material. By changing curing conditions, the optimal curing environment for electromagnetic shielding coating was explored. At the same time, the neutral salt spray test, electromagnetic shielding performance test, and electrochemical impedance test were applied to study the variations in absorption and corrosion resistance of the coating after curing in natural conditions during the salt spray period. Results show that curing under an electromagnetic field can impair the corrosion resistance of the coating. Increasing the content of the absorbing agent was not conducive to improving the absorbing properties of the coating, and impaired the corrosion shielding properties of the coating. After the long-term salt spray test, absorbing properties of the coating decreased with decreasing corrosion shielding properties.