Preparation of Ni-B Coating on Carbonyl Iron and Its Microwave Absorption Properties in the X Band

Ni?B coated carbonyl iron particles (CI@Ni?B) are prepared by the electroless plating technique. The structure, morphology, and antioxidant properties of the CI@Ni-B particles are analyzed. The results demonstrate that the CI particles have been coated with intact spherical-shell Ni-B coating, indicating the core-shell structure of CI@Ni-B particles, and the Ni-B coating can prevent the further oxidation of the CI particles. Compared with the raw CI particles/paraffin coatings with the same coating thickness of 2.0 mm and particles content of 70%, the CI@Ni-B particles/paraffin coatings possess higher microwave absorption (the RL exceeding -10 dB is obtained in the whole X band (8.2–12.4 GHz) with minimal RL of -35.0 dB at 9.2 GHz).