A study on the microstructural reinforcement of aluminous porcelain insulators with high-strength

The aluminous porcelain insulator with high strength was fabricated. The effects of manufacturing parameters such as sintering temperature, duration time on mechanical strengths were analysed in a view of the microstructural reinforcement. The prime factors which improve the mechanical strength is the fertilization of mullite crystal phase and the reinforcement effect of alumina particles dispersed in matrix phase. The simulation results of stress modeling on the real aluminous porcelain insulator by the NASTRAN program indicate that the maximum compressive stress act on the porcelain part of cap lip, then the compressive strength value on it is about 240 /spl square/f//spl square/, which is much lower than the experimental fractural compressive value, 4500 /spl square/f//spl square/. The study of reinforcement mechanism with the thermal stress model of microstructure shows the alumina particles with low thermal expansion coefficient compared to matrix materials act as a barrier protecting the progress of microcrack, as a result it governs the improvement of mechanical strength.