Abstract: To improve the firing yield of ceramic dielectric filters,the surface spots of MgTiO₃-CaTiO₃ (MCT) ceramic dielectric filters fired on corundum-mullite load bearing boards were analyzed by a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDS).The results show that at 1 300 ℃,the filters react with the boards at their contact areas to generate 2MgO·SiO₂ and Al₂O₃·TiO₂,forming discoloration spots.Based on the thermodynamic analysis of the composite oxide reaction,after spraying ZrO₂ coatings on the working surface of the corundum-mullite load bearing boards,the fired filters are of uniform color without discoloration spots.

Key words: ceramic dielectric filters, MgTiO₃-CaTiO₃, corundum-mullite load bearing boards, discoloration spots

摘要： 为提高陶瓷介质滤波器的烧成良品率,采用扫描电子显微镜(SEM)和能谱分析仪(EDS)对MgTiO₃-CaTiO₃(MCT)陶瓷介质滤波器置于刚玉-莫来石承烧板上烧成后出现的表面斑点进行了剖析。结果表明,在 1 300 ℃,MCT陶瓷介质滤波器与刚玉-莫来石承烧板接触点发生反应,生成2MgO·SiO₂和Al₂O₃·TiO₂,形成异色斑点。基于对复合氧化物反应的热力学分析,在刚玉-莫来石承烧板工作面喷涂ZrO₂涂层,烧制的滤波器表面颜色均匀,无异色斑点产生。

关键词: 陶瓷介质滤波器, MgTiO₃-CaTiO₃, 刚玉-莫来石承烧板, 异色斑点