BaTiO_3系PTCR热敏电阻器用烧结助剂的研究

研究了烧结助剂的作用，实验结果表明：如只引入半导化元素，不引入烧结助剂，则室温电阻率ρ２５很大，甚至是绝缘体。由于烧结助剂的加入，既改善了ＰＴＣＲ热敏电阻陶瓷的烧结性，又改善了其ρ２５、耐电压Ｖｂ、ＰＴＣ效应等特性，从而使产品的各种特性易于重复。烧结助剂昔日多用ＡＳＴ，现在常用ＳｉＯ２，其加入量ｘ宜小于２％。ＳｉＯ２的纯度、杂质等化学特性，与粒子形状、粒度分布、晶系等物理特性，对ＰＴＣＲ热敏电阻器的电性能有很大的影响。据此提出了ＢａＴｉＯ３系ＰＴＣＲ热敏电阻器用ＳｉＯ２的技术标准。

Sintering aids for BaTiO 3 PTCR thermistors.

The function of sintering aids is studied. The results show that when dopants for producing semiconductor been added without sintering aids, the resistivity at room temperature ρ 25 may reach very high, even as high as that of a insulator. With the addition of sintering aids, the properties of the PTC thermistor ceramics are improved, such as firing characteristics,ρ 25 , withstanding voltage V b, PTC effect and reproducibility. AST was used as sintering aids but now SiO 2 is commonly used. The quantity x should be less than 2%. The electric performances of PTC thermistor is strongly influenced by the SiO 2's physic properties, such as purity, impurities,and chemical properties, such as particle shape, particle size and crystal system. A set of technical standards for SiO 2 used in PTC thermistors is put forward.(8 refs )