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 。
We have engaged 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 synhesized by laser induced HMDS (((CH3)3Si)2NH) and ammonia. X-ray diffraction, scanning electron microscopy 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 decrease with the increase of SiC(N) powder in sample. 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 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 Si3N4 in the glass, diminishes the formation of nuclei of β-Si3N4 in the glass, and counteracts the growth of β-Si3N4.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2004年第5期618-621,共4页
Journal of Northwestern Polytechnical University
基金
航空科学基金 (0 2 G5 30 4 )资助
关键词
无压烧结
氮化硅
碳化硅
吸波材料
纳米复合材料
Concentration (process)
Dissolution
Nanostructured materials
Powders
Radar
Silicon compounds
Sintering