The electrical properties of some cordierite glass ceramics in the system MgO-Al2O3-SiO2-TiO2
The electrical properties of some cordierite glass ceramics in the system MgO-Al2O3-SiO2-TiO2
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MgO-Al2O3-SiO2-TiO2体系中部分堇青石微晶玻璃的电性能
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
R. Freer
中科院分区：
文献类型：
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作者：
I. O. Owate;R. Freer
的交流用三组不同结晶度的样品研究了MgO-Al_2 O_3-SiO_2-TiO_2系统微晶玻璃的介电击穿和电阻率。标准交流(50 Hz）击穿测试在室温（18 °C）下使用平面圆盘试样和半球形端部黄铜接触电极进行。击穿过程导致形成的击穿通道终止于试样表面的弹坑。击穿强度与电压上升速率无关，但随着试样厚度的增加呈指数下降（60至10 kV mm−1）。高的结晶度含量，良好的表面光洁度和均匀的微观结构产生高的击穿强度，而不良的微观结构的发展造成的击穿强度降低。击穿机制被认为是电子、热和机电过程的组合。
The a.c. dielectric breakdown and electrical resistivity of glass ceramics in the system MgO-Al2O3-SiO2-TiO2 have been studied using three sets of samples having different crystallinity contents. Standard a.c. (50 Hz) breakdown tests were performed at room temperature (18 °C) using planar disc specimens and hemispherically-ended brass contact electrodes. The breakdown process caused the formation of a breakdown channel which terminated at the specimen surface in a crater. The breakdown strength was independent of the rate of voltage rise, but decreased exponentially (60 to 10 kV mm−1) with increasing specimen thickness. A high crystallinity content, good surface finish and a homogeneous microstructure yielded high breakdown strengths whilst poor microstructural development caused a reduction in breakdown strength. The breakdown mechanism is believed to be a combination of electronic, thermal and electromechanical processes.