In recent years, with the radar, the development of microwave communication technology, increasingly complex electromagnetic environment of space, in order to reduce and mitigate electromagnetic radiation on the social environment and human health hazards, the application of electromagnetic wave absorbing materials increasingly widespread, especially for high-frequency, ultra-high frequency microwave absorbing material needs, and promote the research and development of electromagnetic wave absorbing materials. Absorbing material by molding and the carrying capacity of the coating type and structure can be divided into two types, which is coated absorbing materials in its process is simple, inexpensive and widely accepted, widely used in various electronic products, equipment, electromagnetic radiation protection system. However, the use and development at home and abroad are still absorbing material density and high cost, the scope of application subject to certain restrictions.
Hollow glass bubble is a new multi-purpose powder material, a lightweight, good mobility, chemical stability, and low cost, as the space age materials. But hollow glass bubble absorbing powder itself does not have the capacity, the need for its surface modification.
Using high-pressure liquid hydrogen reduction process on the lightweight, low-cost hollow glass bubble powder surface modification, surface test analysis showed: with increasing amounts of nickel, nickel clad powder surface of hollow glass bubble tended to complete . When the amount of nickel wNi up to 50%, the available surface nickel plating covering the complete surface modification hollow glass bubble powder, and the degree of crystallization of nickel particles better.
Test results on the powder surface modification hollow glass bubble electromagnetic parameters indicate that the surface modification hollow glass bubble absorbent powders are electrically lossy dielectric constant with increasing amounts of nickel has improved greatly, permeability small changes.
Nickel-plated surface modification hollow glass bubble powder, powder coating thickness are content and have a greater impact on the performance of the surface-modified hollow glass bubble absorbing coating. Nickel amount wNi as hollow glass bubble wms powder content of 50% and 65%, the coating thickness is prepared when 3mm, which has a good electromagnetic wave absorbent, a minimum reflectance at 9.817GHz -14.555dB, effective absorption bandwidth of 3.1GHz.