Microwave absorbing composite material with silicon carbide-carbon and preparation process thereof

Abstract

The invention relates to a microwave absorbing compounding material that uses silicon carbide as basal material, and the manufacture method. The technology is that: adopting silicon carbide powder that has the diameter of 0.1-10um, graphite C power that has the diameter of 0.1-10um. After molding, the compounding material is sintered at 1700-2250 degree centigrade. The feature is that the density range is 1.6-3.2cm3, resistivity range is 100-104.cm, the real part of dielectric constant is 1-200. The material is machined to sectional area of 22.86*10.16mm2, and the thickness at 4, 8, 12mm, the microwave maximum of attenuation value of the X wave section at 8-12.4GHz is -40db, and the attenuation values in the whole X section are all above -20db.

Description

Technical field: [0001] The present invention relates to a silicon carbide-carbon microwave absorbing composite material and its preparation method, more precisely, it is a composite material with excellent microwave absorbing properties obtained through composition control and process change using silicon carbide and carbon as matrix materials. Materials and their preparation methods. It belongs to the field of ceramic matrix composite materials. Background technique: [0002] Due to its good semiconductor characteristics and other comprehensive properties, silicon carbide ceramics are regarded as a very promising absorbing material. At present, the research in this area is mainly focused on the structural absorbing material with silicon carbide fiber as the absorbent, but due to the expensive price of silicon carbide fiber and the complicated preparation process, the manufacturing cost of this kind of material is high, and it is difficult to obtain a wide range of materia...

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Problems solved by technology

The above-mentioned electrical loss materials have poor microwave absorption performance, and they all need to be controlled by composition and process to obtain better microwave absorption performance.

Taking silicon carbide materials as an example, as reported in the literature [Luo Fa, Zhou Wancheng, Jiao Heng, Zhao Donglin. "Research Status of High-temperature Absorbing Materials." Aerospace Materials Technology. 2000. (1). 8-11] Japan uses the method of purification , to obtain silicon carbide raw materials with extremely high purity and almost no impurities. This material has a wide absorbing frequency band and absorbing performance, but the method is extremely complicated and the manufacturing cost is high

For silicon carbide fibers, as reported in the literature [Song Yongcai, Lu Yi, Feng Chunxiang. "Research and Development of Blended Silicon Carbide Fibers with Microwave Absorbing Properties." Functional Materials. 1997.28 (6). 619] using blended silicon carbide fibers The three-layer structure material can obtain the microwave absorption effect of microwave attenuation above -12dB in the range of 8-12GHz, but the biggest disadvantage is also the high cost and complicated process

As for magnetic loss absorbing materials such as ferrite [Amin M B, James J R. "Techniques for utilization of hexagonal ferrites in radar absorbers." The Radar and Electronic Engineer.1981.57(5).209-214], although electromagnetic waves are easy to enter It is used in the field of microwave absorption due to its internal and fast attenuation, but its application range is limited due to its high density and poor temperature stability

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