| Corundum-mullite, featured with high melting point, good creep resistance, good thermal shock resistance and high cost-effectiveness, is widely used to manufacture kiln furniture materials. Compared with the similar products overseas, the main problems of domestic corundum-mullite furnitures are their worse thermal shock resistance and integrated performance. In order to improve the performance of corundum-mullite materials, transition plastic phase process was adopted and the influences of aluminum and elementary silicon additives and their addition amounts on corundum-mullite materials were studied by using andalusite, tabular corundum, alumina micropowder and silica micropowder as starting materials, and with 0, 1%, 2% and 3% addition of aluminum or elementary silicon as additives, respectively.The influences of aluminum and elementary silicon on bulk density, strength, toughness and thermal shock resistance of corundum-mullite materials were studied, respectively. The results showed that both aluminum and elementary silicon could lead to plastic shaping in corundum-mullite materials. Aluminum or silicon in-situ oxidized and formed new oxide, decreased the apparent porosity by filling part of the air-holes. The new oxide, featured with high activity, reacted with the matrix and formed mullite. The new obtained mullite crystals were needle-like and interleaved with others, which could improve the strength, toughness and thermal shock resistance of the materials. Due to the low density of aluminum or elementary silicon, their additions decreased the bulk density of the materials.Compared with elementary silicon, aluminum improved the performance of the materials more obviously. |
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