【摘要】 利用激光诱导法制备的纳米 Si C和 LAS玻璃粉米 ,采用热压法制备纳米 Si C/ LAS陶瓷复合材料 ,研究了纳米 Si C/ LAS陶瓷复合材料微波介电性能与纳米 Si C含量、烧结温度以及碳界面层的关系。结果表明 ,在 1 0 80℃以下烧结温度对陶瓷致密度的影响较大而对陶瓷复介电常数的影响较小 ;但在 1 0 80℃以上烧结温度对烧结致密度的影响较小 ,而对陶瓷复介电常数的影响较大 ,复合材料复介电常数的实测值与计算值之间存在很大的差异。通过计算和分析认为 ,复合材料制备过程中纳米尺度的 Si C促进了碳界面层形成 ,使得烧结温度对复合材料复介电常数有很大影响更多还原

【Abstract】 One item in the contract we signed is to study the effect of interface on permittivity of nanometer SiC/LAS ceramic composite. Subsection 2.3 presents the main results of our research. Subsubsection 2.3.1 gives the experimentally determined effect of different nano SiC contents——3, 5, 7, 10 wt%——on permittivity of nanometer SiC/LAS ceramic composite; the sintering pressure was 15 MPa and the sintering temperature for 30 min was 1 080℃; Fig.2 gives the variations of ε′ (real part) and ε" (imaginary part )of permittivity with nano SiC content. Subsubsection 2.3.2 gives the experimentally determined effect of different sintering temperatures——1 000℃, 1 080℃, 1 150℃ for 30 min——on permittivity and density after sintering of nanometer SiC/LAS ceramic composite; the nano SiC content was approximately 5wt%; Fig. 3 shows the variations of density after sintering, ε′ and ε" with sintering temperature. Fig. 4 gives variations of ε′ and ε" with nano SiC content computed with Polder Van Santen formula. Computed results in Fig. 4 differ much from experimental results in Fig. 2. Subsubsection 2.3.3 discusses the cause for this big discrepancy; this discrepancy is very likely due to the high permittivity of the carbon rich interface; the higher activity and the higher specific surface area of nano SiC facilitate the interface formation and intensify its influence on the permittivity of the SiC/LAS composite.更多还原