Microstructures and Properties of Stanchion Insulator Ceramics

Microstructures and properties of two typical stanchion insulator ceramics were investigated by means of analysis on chemical composition, phase, microstructure, mechanical properties and thermal shock resistance. The results showed that for the siliceous insulator ceramics, they had more mullite in phase composition and lower density. The amount of the pores was larger and the roundness of them was lower. Moreover, the remained silica particles were embedded into ceramic matrix. On the Contrary, the alumina insulator ceramics were richer in Al2O3, having less pores and higher density. The pores in them were more spherical, and the remained Al2O3 particles contacted tightly with the matrix. Therefore, the alumina insulator ceramics had higher bending strength and elastic modulus, but the siliceous insulator ceramics had higher thermal shock resistance.