摘要
本文系统研究了国内两个厂家生产的550 kN特高压用氧化铝瓷和铝矾土瓷在组成、结构与力学性能方面存在的差异,并分析总结了铝矾土瓷比氧化铝瓷劣化率高的原因。结果表明:(1)对于铝矾土瓷,由于使用了Fe_(2)O_(3)、TiO_(2)含量高的煅烧铝矾土为高铝原料,两个铝矾土瓷的Fe_(2)O_(3)&TiO_(2)含量分别为3.51%和3.56%,是两个氧化铝瓷的3倍以上;(2)氧化铝瓷在配方中加入了一定量的石英原料,所以两个氧化铝瓷的石英相含量(分别为6.29%和7.00%)明显高于铝矾土瓷,而铝矾土瓷中的莫来石除了从高岭土的分解产物偏高岭石中生成的一次莫来石和从富铝的长石熔体中析出的针状二次莫来石外,还有来自煅烧铝矾土原料,因此铝矾土瓷的莫来石含量(分别为12.59%和14.91%)高于氧化铝瓷;(3)两个铝矾土瓷的真气孔率分别为10.62%和9.62%,明显高于氧化铝瓷;(4)铝矾土瓷的三点弯曲强度平均值分别为140 MPa和148 MPa,比氧化铝瓷低20 MP以上,而且强度分散性更大。铝矾土瓷内部存在的扁平、细长、裂纹状以及聚集型、联通型气孔,以及带孔刚玉聚集体和粗大棱柱状莫来石聚集体等结构不均匀现象,是导致其强度低、分散性大、劣化率高的根本原因。
In this paper,the differences in composition,structure and mechanical properties of alumina and bauxite insulators for ultra high voltage(UHV)from two domestic manufacturers were systematically studied,and the reasons for the higher deterioration rate of bauxite insulator compared to alumina insulator were analyzed and summarized.The results show that for bauxite insulator,due to the use of calcined bauxite with high Fe_(2)O_(3)and TiO_(2)contents as high aluminum raw materials,the Fe_(2)O_(3)and TiO_(2)contents of the two bauxite insulators are 3.51%and 3.56%,respectively,which are more than three times that of the two alumina ceramics.(2)A certain amount of quartz raw material is added to the formula of alumina insulators,so the quartz phase content of the two alumina ceramics(6.29%and 7.00%,respectively)is significantly higher than that of bauxite insulators.In addition to primary mullite generated from metakaolinite(decomposition product of kaolin),and needle like secondary mullite precipitated from the aluminum rich feldspar melt,the mullite in bauxite insulators also comes from calcined bauxite raw materials,therefore,the mullite content of bauxite insulators(12.59%and 14.91%,respectively)is higher than that of alumina ceramics.(3)The true porosity of the two bauxite insulators is 10.62%and 9.62%,respectively,which is significantly higher than that of alumina insulators.(4)The average value of the three-point bending strength of bauxite insulators is 140 MPa and 148 MPa,respectively,which are more than 20 MP lower than that of alumina insulators,and the strength dispersion are greater.The flat,slender,cracked,aggregated,and interconnected pores,as well as uneven structures such as porous corundum aggregates and coarse prismatic mullite aggregates,exist inside bauxite insulators,which are the fundamental reasons for their low strength,high dispersibility,and high deterioration rate.
作者
栾艺娜
杨海
赖群
袁志勇
LUAN Yi-Na;YANG Hai;LAI Qun;YUAN Zhi-Yong(Shandong University of Technology,Zibo,255000,China;Sinoma Jiangxi Insulator and electricity Co.,Ltd.,Pingxiang 337200,China;Luxi High Voltage Insulator and Electricity Research Institute Co.,Ltd.,Pingxiang 337200,China)
出处
《现代技术陶瓷》
CAS
2024年第3期279-291,共13页
Advanced Ceramics
关键词
特高压
氧化铝瓷
铝矾土瓷
显微结构
性能
uHV
alumina insulator
bauxite insulator
microstructure
properties
