Abstract: SiO2-Al2O3 ceramic microspheres were fabricated by particle-stabilized foams method combining with centrifugal spray drying process, where high purified quartz powder, alumina powder and glass powder were chosen as raw materials.Then, SiO2-Al2O3 ceramic microspheres were closely packed in the crucible, followed by directly sintering at 1500 ℃ for 1 h and porous mullite ceramics with well distributed pores were prepared through self-foaming process at elevated temperature.The effect of raw materials compositions on the properties of porous mullite ceramics has been studied.This novel method is simple, convenient, and controllable.Porous mullite ceramics with high porosity of 85.4;, compressive strength of (3.69±0.86) MPa, and low dielectric constant of 1.70 was obtained by this method which could be applied to the wave-transparent materials field.

Key words: SiO2-Al2O3 ceramic microspheres were fabricated by particle-stabilized foams method combining with centrifugal spray drying process, where high purified quartz powder, alumina powder and glass powder were chosen as raw materials.Then, SiO2-Al2O3 ceramic microspheres were closely packed in the crucible, followed by directly sintering at 1500 ℃ for 1 h and porous mullite ceramics with well distributed pores were prepared through self-foaming process at elevated temperature.The effect of raw materials compositions on the properties of porous mullite ceramics has been studied.This novel method is simple, convenient, and controllable.Porous mullite ceramics with high porosity of 85.4;, compressive strength of (3.69±0.86) MPa, and low dielectric constant of 1.70 was obtained by this method which could be applied to the wave-transparent materials field.