In this paper, α-CaSiO₃/Al₂O₃-Li₂CO₃ was prepared by traditional solid-state method with Li₂CO₃ as low-temperature sintering aid added to α-CaSiO₃/Al₂O₃ ceramics. The effects of different Li₂CO₃ content on the sintering properties, microstructure, and microwave dielectric properties of α-CaSiO₃/Al₂O₃ ceramics were studied. The phase structure, micro-morphology, and microwave dielectric properties were characterized by X-ray diffractometer, scanning electron microscope, and network analyzer. The aim of this paper is to reduce the sintering temperature and improve the microwave dielectric properties of α-CaSiO₃/Al₂O₃ ceramics by controlling the phase structure of ceramics. The results revealed that Li₂CO₃ additives can not only reduce the sintering temperature from 1375 to 975 °C, but also can transfer the major phase composition from α-CaSiO₃ to β-CaSiO₃. The density of the microwave dielectric ceramics with 3 wt% Li₂CO₃ additives sintered at 975 °C can reach the optimal microwave dielectric properties with ε_r = 6.21, Q × f = 30,471 GHz, and τ_f = − 34.58 ppm/°C.

本文采用传统固相法制备α- CaSiO ₃ /Al ₂ O ₃ -Li ₂ CO ₃，将Li ₂ CO ₃作为低温烧结助剂加入α- CaSiO ₃ /Al ₂ O ₃陶瓷中。不同Li ₂ CO ₃含量对α- CaSiO ₃ /Al ₂ O ₃烧结性能、微观结构和微波介电性能的影响陶瓷进行了研究。通过X射线衍射仪、扫描电子显微镜和网络分析仪对相结构、微观形貌和微波介电特性进行了表征。本文旨在通过控制陶瓷的相结构来降低α- CaSiO ₃ /Al ₂ O ₃陶瓷的烧结温度，提高其微波介电性能。结果表明，Li ₂ CO ₃添加剂不仅可以将烧结温度从1375℃降低到975℃，而且可以将主相组成从α- CaSiO ₃转移到β- CaSiO ₃. 在 975 °C 下烧结含有 3 wt% Li ₂ CO ₃添加剂的微波介电陶瓷的密度可以达到最佳微波介电性能，ε _r  = 6.21，Q  ×  f  = 30,471 GHz，τ _f  = − 34.58 ppm/° C。