【摘要】 通过掺杂纳米 Si C( N)吸收剂 ,采用无压烧结工艺 ,制备了 Si C( N) /Si3 N4复合型吸波材料。对材料进行了 XRD、SEM及强度分析 ,结果表明 :随着纳米吸收剂 Si C( N)加入量的增加 ,材料的烧结性能趋于下降 ,表现为 α- Si3 N4的含量增多 ,柱状 β- Si3 N4的尺寸变小 ,材料气孔增大 ,强度降低更多还原

【Abstract】 We have engaged, are engaging, and will engage in a long-term project of obtaining high-quality RAM （radar wave-absorbing materials）. Pressureless sintering process is promising for preparing SiC（N）/Si₃N₄, a type of RAM. But such preparation may bring with it disagreeable features. Our aim is to investigate the causes of these possible disagreeable features in preparation for discovering how to prepare satisfactory SiC（N）/Si₃N₄. SiC（N） powder was syntesized by laser induce of HMDS （（（CH₃）₃Si）₂NH） and ammonia. XRD, SEM and strength analyses were performed on the samples. The results show that the sintering density, the content and size of β-Si₃N₄ and the strength of SiC（N）/Si₃N₄ all decrease with increasing content of SiC（N） powder in sample. After repeated thinking and discussion, we believe that the addition of SiC（N） powder to Si₃N₄ enhances the glutinosity of glass formed during sintering process by sintering additives and SiO₂ film on the surface of Si₃N₄ during sintering process by sintering addivtives and SiO₂ film on the surface of Si₃N₄ and thus lowers the sintering density of the sample. We believe that the higher glutinosity retards the dissolution of α-Si₃N₄ into it, reduces the concentration of Si₄N₄ in the glass, diminishes the formation of nuclei of β-Si₄N₄ in the glass, and counteracts the growth of β-Si₃N₄.更多还原