Preparation method and product for coating a modified flaky FeSiAl absorbent

The invention discloses a preparation method and a product for coating a modified flaky FeSiAl absorbent. The coating and modification process adopts the monomer polymerization method, and the uniform and complete modification of the flaky FeSiAl magnetic powder can be achieved by controlling the process conditions. The preparation process is as follows: (1) uniformly dispersing 10 to 15 parts of flaky FeSiAl magnetic powder and 0% 3 to 0.5 parts of coupling agent in 75 to 80 parts of binary solvents of alcohols and benzene and adding 0.1 to 0.3 part of azo initiator; (2) under the protection of inert gas, slowly adding 2 to 4 parts of styrene monomer to react at 70 to 75 temperatures for 5 to 7h; and (3) finally cooling, centrifuging and drying to obtain a surface coated with a layer of uniform dense polystyrene sheet like FeSiAl absorbent, the above parts being all by weight. The coated modified flaky FeSiAl absorbent prepared by the invention has good insulation property and excellent microwave absorption performance, and the obtained reflectivity is better than 10dB in the frequency band of 2-18GHz up to 7.48GHz; and the conditions for the preparation process are mild and convenient, and the efficiency is high, enabling the industrial production.