Increasing Resistivity of Electrically Conductive Ceramics by Insulating Grain Boundary Phase
Increasing Resistivity of Electrically Conductive Ceramics by Insulating Grain Boundary Phase
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DOI：
10.1021/am4052766
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发表时间：
2014-02-26
影响因子：
9.5
通讯作者：
Sekino, Tohru
中科院分区：
文献类型：
--
作者：
Kusunose, Takafumi;Sekino, Tohru
通过添加绝缘晶界相来绝缘烧结体中的导电颗粒的导电路径，研究了导电非氧化物陶瓷的电阻率增加，所述绝缘晶界相是通过液相烧结中的烧结添加剂的反应产生的。当添加10vol%Al_2O_3和Y_2O_3热压SiC时，由于致密化过程中SiC颗粒之间的接触，电阻率随烧结温度的升高而降低。然而，通过在1750 ℃下热压，由于SiC晶粒之间的绝缘晶界相的渗透，实现了大于1 × 10（11）Ω cm的高电阻率。通过引入绝缘晶界相，可以制造高电阻率SiC陶瓷，而不损失其优异的机械性能，所述绝缘晶界相的体积约为常规陶瓷复合材料中引入的绝缘相的1/7。
Increasing resistivity of electrically conductive nonoxide ceramics was investigated by insulating conductive pathways through conductive grains in a sintered body by addition of an insulating grain boundary phase, which was produced by the reaction of sintering additives in liquid phase sintering. When SiC was hot pressed with an additive of 10 vol % of Al2O3 and Y2O3, the resistivity decreased as sintering temperature increased owing to contact between SiC grains during densification. However, by hot pressing at 1750 degrees C, a high resistivity of greater than 1 X 10(11) Omega cm was achieved because of the penetration of an insulating grain boundary phase between the SiC grains. It is possible to fabricate high-resistivity SiC ceramics without losing their excellent mechanical properties by introduction of an insulating grain boundary phase, the volume of which is approximately 1/7 that of the insulating phase incorporated in conventional ceramic composites.