Because andalusite, sillimanite and kyanite change into mullite at high temperature, and the expansion coefficient of mullite is small, it is beneficial to improve the thermal shock resistance of the material. The addition of andalusite to the material can form numerous fine pores of thermal stress diffusion, which can release the stress generated in the interior of the refractory due to expansion and contraction, thus improving the thermal shock resistance of the material. The temperature of complete Mullitization of sillimanite is higher, which is favorable for improving the high temperature creep resistance of products. In addition, the volume expansion effect of Mullitization is also beneficial to creep resistance at high temperature.
It is pointed out that the creep resistance of andalusite brick is better than that of common high alumina brick, corundum brick and most mullite brick. Therefore, the development and utilization of "three stones" to improve the microstructure and thermodynamic properties of Al Si refractories has great application space.
