Effects of annealing and firing in wet hydrogen on the dielectric breakdown strengths of alumina ceramics  

作　　者：Jishi DU Binghua TANG Wei LIU Tao ZhANG Jiagen PENG Hu CHEN Yangjun LEI 

机构地区：[1]Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang,621900,China [2]Department of Materials Science,Sichuan University,Chengdu,610064,China

出　　处：《Journal of Advanced Ceramics》2020年第2期173-182,共10页先进陶瓷（英文）

基　　金：The study was financially supported by the Science Development Foundation of China Academy of Engineering Physics(2014A0302012);the Funding Support by Laboratory of Precision Manufacturing Technology,CAEP(ZD18001).

摘　　要：Annealing and firing in wet hydrogen are widely used steps in the processing alumina.ceramic insulators that may affect their dielectric breakdown strengths(DBS).In this study,the effects of annealing(at 1300℃for 7 h)and firing in wet hydrogen on the DBS of alumina ceramics(all sintered at 1650℃)were studied,and the underlying mechanisms were analyzed by material characterizations.Annealing reduced the DBS of the 95%alumina ceramics due to the inter-granular phase crystallization,and the reduction in the DBS could be correlated to the reduction in mechanical strength.In contrast,annealing improved the DBS of the 99%alumina ceramic without intergranular phase transformation.Firing in wet hydrogen at 1500℃caused the DBS increment,which can be ascribed to the reduction in the concentrations of point defects and electrical carriers.

关 键 词：alumina ceramic dielectric breakdown strength(DBS) inter-granular phase crystallization firing in wet hydrogen 

分 类 号：TQ174.758.11[化学工程—陶瓷工业]