Thermal Conductivity and Bending Strength of Porous Mullite Ceramics Made by PFA Method Using Corn Starch

Abstract

Porous ceramics are widely used in filter, thermal insulation and acoustics applications. This research aims to produce porous mullite ceramics by PFA (Pore-Forming Agent)method using corn starch as the agent. Various contents of corn starch of 0, 5, 10, 15, 20 and 25 % weight were added to kaolin powder. Each composition was uniaxially pressed to produce green body. The green body of monolithic kaolin was pressureless sintered in air at various temperatures of 1000, 1100, 1200, 1300, 1400 and 1450 oC for two hours. Temperature of 1450 oC was chosen for producing porous mullite ceramics. Relative density, bending strength and thermal conductivity were measured on the sintered body. The results show that the porosity of the mullite ceramics increases with increasing corn starch contents. The bending strength and thermal conductivity of the porous mullite ceramics decrease with increasing porosit