Li_2CO_3改性CBS/Al_2O_3玻璃-陶瓷的性能

Low Temperature Sintering and Performance of CBS/Al_2O_3 Glass—Ceramic Doped With Li_2CO_3

以CaO-B_2O_3-SiO_2(CBS)玻璃粉体和Al_2O_3陶瓷粉体为原料,在CBS/Al_2O_3质量比固定为50/50的玻璃-陶瓷中添加适量的Li_2CO_3作为烧结助剂,研究了Li_2CO_3添加量对CBS/Al_2O_3玻璃-陶瓷的烧结性能、机械性能以及介电性能的影响.结果表明,Li_2CO_3可改善CBS玻璃的结构,降低其软化点温度和黏度,与Al_2O_3反应生成低共熔相LiAlO_2;这些因素的协同作用促进了CBS/Al_2O_3玻璃-陶瓷的致密化进程,在830℃烧结即能获得结构较致密、气孔较少的CBS/Al_2O_3玻璃-陶瓷.但是,添加过量的Li_2CO_3将因锂化合物的挥发而恶化CBS/Al_2O_3玻璃-陶瓷的烧结性能、介电性能及机械性能.当Li_2CO_3添加量(质量分数)为0.50%时,在830℃烧结后获得结构最为致密的CBS/Al_2O_3玻璃-陶瓷,其密度为2.76 g·cm^(-3),并具有良好的介电性能和机械性能.

CBS/Al2O3 glass-ceramic was prepared by using CaO-B2O3-SiO2 （CBS） glass and Al2O3 powders as the raw materials with the mass ratio of 50/50, and the influence of the additive of Li2CO3 on the sintering property, dielectric property and mechanical properties of CBS/Al2O3 composites was investigated. The results show that the additive of Ll2CO3 can lower the softening point and viscosity of CBS glass by modifying the structure of CBS glass, and can react with Al2O3 to form low melting phase of Li2AlO2, which can promote the sintering process of CBS/Al2O3 glass-ceramic and result in lowering down the sintering temperature to 830℃. However, the excess Li2CO3 can deteriorate the dielectric property and mechanical properties of CBS/Al2O3 glass-ceramic because of the volatilization of Li-compounds. With 0.50% Li2CO3 addition, the CBS/Al2O3 glass-ceramic could be sintered at 830℃ and obtained excellent properties.