Mechanical evaluations of mullite fibrous ceramics processed by filtration and in situ pyrolysis of organic precursor

Abstract Highly porous mullite fiber-based ceramics with a three-dimensional cross structure were successfully designed and fabricated by filtration method. To address the thermal migration of silica sol, polysiloxane was introduced in the bonding system as high temperature binder to form more stable nods in the skeleton as opposed to silica sol which would migrate to the surface of fibers during the sintering process. Due to the lapped structure of mullite fibers, all products showed high porosity(74.1%∼80.9%), low density(0.554g/cm3∼0.608g/cm3) and relatively low thermal conductivity(