Dielectric breakdown characteristics of alumina
Dielectric breakdown characteristics of alumina
复制标题
氧化铝的介电击穿特性
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
D. Malec
中科院分区：
文献类型：
--
作者：
F. Talbi;F. Lalam;D. Malec
研究了氧化铝陶瓷的交流50 Hz正弦介质击穿与厚度（0.127 ~ 2.54 mm）和纯度（92%、96%和99.5%）的关系。结果表明，介电强度随厚度的增加而减小，随纯度的增加而增大。此外，使用扫描电子显微镜（SEM）的fallure形态的调查显示，每个标本提交到击穿的存在下，一个通道终止于一个火山口的表面。这个坑是由于在局部电应力加剧引起的击穿过程中物质的提取和喷射造成的。还观察到了弹坑尺寸随样品厚度的变化。实验结果和SEM观察的分析证实，建立的火山口是一个关键的步骤，在介电击穿过程中，最适合描述这些材料的介电击穿的机制是基于机电之一。
The AC 50 Hz sine dielectric breakdown of alumina ceramics versus thickness (0.127 to 2.54 mm) and purity (92%, 96% and 99.5%) was investigated. The results have shown that the dielectric strength decreases with the thickness and increases with the purity. Furthermore, the investigation of the faillure morphology using the scaning electron microscopy (SEM) show for each specimens submitted to breakdown the presence of a canal terminated by a crater at the surface. This crater is resulting from the extraction and ejection of the matter during the breakdown process caused by the intensification of the local electric stress. An evolution of the crater size versus the sample thickness have also been observed. The analysis of the experimental results and the SEM observations confirm that the built up of the crater is a crucial step in dielectric breakdown process and the mechanism best suited to describe the dielectric breakdown in these materials is based on an electromechanical one.