Ni/(Ba,Sr)TiO_3复合PTC材料的显微结构和电性能(英文)

MICROSTRCTURE AND ELECTRICAL PROPERTIES OF Ni/(Ba,Sr)TiO_3 PTC COMPOSITE

应用X射线衍射、光学金相显微镜、环境扫描电镜和透射电镜分析Ni/(Ba,Sr)TiO3复合正温度系数(positive temperature coefficient,PTC)材料的显微结构。结合显微结构的分析结果研究了复合PTC材料的电性能。结果表明:在石墨粉造成的还原气氛下烧结后,金属Ni主要以单质态存在。复合材料中添加PbO–B2O3–ZnO–SiO2玻璃料有利于金属Ni在(Ba,Sr)TiO3陶瓷基质中的均匀分布。玻璃料引入的晶间相以无定形态存在于陶瓷晶粒和金属晶粒之间的界面以及这些晶粒围成的区域,玻璃料形成的晶间相和陶瓷之间没有明显的扩散。适量玻璃料的加入有助于室温电阻率的降低、PTC效应的改善和耐电压强度的升高,但是过多玻璃料的加入,不利于制备性能优良的复合PTC材料。

The X-ray diffraction,optical metalloscopy,environmental scanning electron microscope,and transmission electron microscope were carried out to investigate the microstructure of Ni/(Ba,Sr)TiO3 positive temperature coefficient(PTC) composite.Based on the microstructural analysis,the composite electrical properties were discussed.The results show that nickel is mainly the simple substance state after sintering under a reducing atmosphere produced by graphite powder.After the addition of PbO-B2O3-ZnO-SiO2 glass...