掺杂Li_2O-K_2O-Al_2O_3石英陶瓷的性能研究

Study on the Properties of Silica Ceramic Doping Li_2O-K_2O-Al_2O_3

采用固相烧结法烧结掺杂Li2O-K2O-Al2O3石英陶瓷,用XRD、SEM、微波网络分析仪等手段分析不同烧结温度下样品的表面特性、介电性能及力学性能。结果表明,掺杂Li2O-K2O-Al2O3石英陶瓷在烧结过程中产生了大量玻璃相,陶瓷微结构致密,介电性能良好（低频1 MHz测试下介电常数εr=5.45~5.87,损耗角正切tanδ=0.004 1~0.005 4;高频14GHz测试下εr=4.37~4.58,损耗角正切为0.003 8-0.005 3）,在1 350℃烧结陶瓷介电性能最优。相比不掺杂石英陶瓷抗弯强度有显著提高,在145MPa以上,最高可达163MPa。有作为天线罩材料的潜力。

The silica ceramic doped Li2O-K2O-Al2O3 was sintered using the solid-state reaction technique. The samples at different sinter-temperatures were analyzed by microwave network analyzer, SEM and XRD etc. It was found that the ceramic doped Li2O-K2O-Al2O3 almost melt into glass state when sintering. The microstructure of the ceramic was pyknotic and the dielectric properties were pretty good. At the measured frequency of 1 MHz, the dielectric constant were 5.45-5.87 and the dielectric loss were 0. 004 1-0. 005 4. At the measured frequency of 14 GHz, the dielectric constant were 4.37-4.58, the dielectric loss were 0. 003 8-0. 005 3. The ceramic had the best dielectric property at the sinter-temperature of 1 350 ℃. The bending strength of the silica ceramic doped Li2O-K2O-Al2O3 was much better than the silica ceramic without doping. The bending strength was all above 145 MPa, or even to maximum 163 MPa. The silica ceramic doped Li2O-K2O-Al2O3 had the potential to be one of the radome materials.