MnNiCuFe系材料的聚合络合法制备及微波烧结

Microwave sinter of Mn_(0.43)Ni_(0.90)CuFe_(0.67)O_4 thermistor materials prepared by polymerized complex method

为了得到低B值(2100K)、高精度互换、均匀性好的NTC热敏电阻器,采用聚合络合法制备了Mn0.43Ni0.90CuFe0.67O4 NTC热敏材料的前驱体,在500℃进行热分解后获得氧化物,经不同温度微波煅烧,确定最佳温度后成型,分别进行微波烧结与常规烧结。采用TGA-DTA、FT-IR、XRD、粒度分析及SEM等手段,对材料进行表征。结果表明:微波煅烧最佳温度为650℃,陶瓷体由缺铜相和富铜相两相组成;微波烧结大大提高了元件的均匀性,成品率由常规烧结的30%提高至85%。

In order to obtain NTC thermistor with low B value （2 100 K）, high-precision, exchange-type and fine homogeneity, Mn0.43Ni0.90CuFe0.6704 NTC thermistor material precursors were prepared by the polymerized complex method. The oxide mixtures were attained from calcining of the polymerized gel precursor at 500℃ and then were microwave-calcined at different temperatures to determine the optimum temperature. The materials were then microwave and conventionally sintered after forming. The materials were characterized by TGA-DTA, Fr-IR, XRD, particle size analyzer, SEM and EDS. The experimental results indicate that the particles microwave calcined at 650℃ were small and uniform. The ceramics mainly consist of rich-Cu phase and poor-Cu phase. The homogeneity of components is significantly increased by microwave sinter. Moreover, the rate of finished products is increased to 85% from 30% compared with the one of conventional sinter.