Method for producing semi-structure SiC-ferrite ceramic composite electromagnetic wave absorber

摘要

PROBLEM TO BE SOLVED: To develop an electromagnetic wave absorbing body which is excellent in fire resistance and durability, and effective in 1-20 GHz band area, by using a novel material. SOLUTION: The electromagnetic wave absorbing body of a quasi-structural SiC ferrite-based ceramic composite is composed of a spinel ferrite sintering material containing quasi-structural SiC, and possesses matching frequencies to electromagnetic waves between 100 MHz-10 GHz. A spinel ferrite powder is mixed with an infusibilized polycarbosilane 5-30 wt.% based on the ferrite powder weight; or a spinel ferrite powder is mixed with a solvent dissolving and containing polycarbosilane 3-10 wt.% based on the ferrite powder weight, and thereafter a mixture resulted from volatilization of the solvent is infusibilized. The mixed powder produced by either of the above two steps is press-formed, sintered at 900-1,200 deg.C in a nonoxidizing atmosphere, and furthermore burned at 900-1,200 deg.C in an oxidizing atmosphere. By this two-stage heating, quasi-structural SiC is formed in the sintering material.