为了满足6G太赫兹频段低时延通信技术的要求, 采用冷冻干燥法制备了具有超低介电常数的定向通孔结构多孔氧化铝陶瓷。研究不同部位样品的结构与性能关系, 以及固相含量对微观形貌、力学性能、太赫兹光学和介电性能的影响。获得具有高气孔率(68.9%~81.0%)、高抗压强度(17.6~87.8 MPa)的多孔氧化铝陶瓷, 在1 THz下具有超低的折射率(1.38~1.63)、吸收系数(~2.5 cm-1)、介电常数(1.90~2.67)和介电损耗(~0.008)。定向通孔结构在与气孔平行的方向具有高抗压强度, 其特殊的结构在太赫兹波导和天线基板等方面有重要的潜在应用价值。

To meet the requirements of low-latency communication technology in the 6G terahertz band, porous alumina ceramics with ultra-low dielectric constant and directional pore channels were prepared by a freeze-drying method. A relationship between the structure and the properties of samples from different locations was investigated. The effect of solid content on the microstructure, mechanical properties, terahertz optical and dielectric properties was analyzed. Porous alumina ceramics with high porosity (i.e., 68.9%-81.0%) and compressive strength (i.e., 17.6-87.8 MPa) can be obtained, having ultra-low refractive index (i.e., 1.38-1.63), absorption coefficient (i.e., ~2.5 cm-1), dielectric constant (i.e., 1.90-2.67), and z dielectric loss (i.e., ~0.008) at 1 THz. The directional pore channels exhibit high compressive strength in the direction parallel to the pores, and the special structure has potential applications for terahertz waveguides and antenna substrates.