Research progress of alumina-based absorbing materials

Abstract

Radar absorbing materials (RAM) play an important role in the defense field. Thin, light mass, broad bandwidth, and strong absorption are required for the RAM in current research filed. Weapons and equipment flying at high Mach make the local temperature of the body very high due to air resistance, and the absorbing materials at room temperature can not be applied. It is urgent to study the absorbing materials which can resist high temperature and absorb electromagnetic wave efficiently. High temperature resistant and high temperature absorbing materials prepared by composite of different types of absorbents with alumina as the matrix have been widely concerned and studied. The metal (alloy)/alumina, non-metal/aluminum, and other alumina-containing composite absorbing material systems are deeply discussed, and the current research status of alumina-based composites are systematically summarized in this paper. The structure, properties and absorption mechanism of composite absorbers prepared by different structures (nanowires, microspheres and nanoparticles) and alumina matrix of various forms (porous membranes, fibers or nanoparticles) are analyzed. It was also prospected about the future development of the metal (alloy)/alumina and non-metal/aluminum composite absorbing material. In the metal (alloy)/alumina composite absorbing material system, it should be: (1) to develop the nanoscale spherical ultrafine metal absorbing agent and the wave absorption performance using the special effect of nanoparticles; (2) to achieve good absorbent and matrix matching by further exploring the reasonable preparation technology. In nonmetallic/alumina composite absorbing material system, it should be: (1) further to strengthen the research on the composite of alumina fiber cloth and alumina mesh matrix with nano absorbent; (2) to strengthen the study of polymer special core-shell structure and impedance matching layer; (3) to strengthen the study of the modification of wide band absorbing materials and absorbing agents; (4) to study the inorganic matrix composed of metal oxide powder and inorganic binder.

Keywords

• alumina
• high temperature absorbing properties
• absorbing materials
• current research state