陶瓷电容器镍电极的致密化过程

Densification process of Ni electrodes in ceramic capacitors

分别在550、650、750和950℃的烧结温度下制备陶瓷电容器贱金属镍电极。研究了烧结温度对镍电极附着力和方阻的影响,分析了不同烧结温度下镍电极的微观组织和成分,揭示了镍电极致密化过程的本质。结果表明,随着烧结温度的增加,镍电极附着力逐渐增大,方阻逐渐下降;烧结温度是影响镍电极致密化过程的重要因素,950℃时形成了连续、致密的三层结构电极,中间层与镍电极附着强度相关;镍电极的致密化过程分为液态玻璃的生成、镍粉颗粒的溶解析出和固相骨架的形成3个阶段。

The Ni base metal electrodes in ceramic capacitors were prepared at sintering temperature of 550, 650, 750 and 950 ℃, respectively. In order to elucidate the densification process mechanisms of Ni electrodes, the effects of sintering temperature on the adhesion and square resistance of Ni electrodes were studied, and the microstructures and compositions of Ni electrodes at various sintering temperatures were analyzed. With the increase of the sintering temperature, the adhesion force of Ni electrodes enhances, and the square resistance decreases. The SEM and EDS results show that the sintering temperature has a significant effect on the densification process of Ni electrodes. A continuous and compact electrode with the three-layer structure is formed at 950 ℃, and the adhesion strength of Ni electrodes is dependent on the middle layer. The densification process of Ni electrodes include three stages, such as the formation of liquid glass, the dissolution and precipitation of Ni particles and the formation of solid framework.