Porous mullite-corundum ceramics were prepared using organic foam impregnation method with alumina and silica as raw materials. The influence of alkaline treatment and surfactant modification on polyurethane foam were studied. Effects of sintering process and material composition on porous mullite-corundum ceramics were investigated. The results show that the hang-pulp quantity of polyurethane foam increases with alkaline treatment. After treatment with 3 wt% SDS solution, the hang-pulp quantity of polyurethane foam further improved. Open porosity of sample decreased with elevation of sintering temperature and holding time, and compressive strength of sample showed a trend opposite to the change of porosity. The open porosity of the sample was enhanced by the increase of m(Al2O3/SiO2); the compressive strength decreased with increase of m(Al2O3/SiO2). However, when m(Al2O3/SiO2) was 2.5, the compressive strength of the sample reached 6.23 MPa, and the open porosity of the sample was 80.7 %.

Abstract
1. Introduction
2. Experimental Procedure
    2.1. Raw materials
    2.2. Pretreatment of foam polyurethane
    2.3. Preparation of porous mullite-corundum ceramics
    2.4. Characterization
3. Results and Discussion
    3.1. Pretreatment of foam polyurethane
    3.2. Structural analysis of porous mullite-corundumceramics
    3.3. Physical properties of porous mullite-corundumceramics
    3.3. Sintering mechanism of porous mullite-corundumceramics
References

• Xianzhi Zhou
• Shaofeng Zhu Corresponding author
• Yuxi Wang
• Tong Zhang