The effect of sintering temperatures on alumina foam strength

An idea to improve the strength of ceramic foams by controlling the sintering temperature was proposed in this paper. The effect of sintering temperatures on alumina foams strength was investigated by discussing three factors: shrinkage, porosity and grain size, which changed with sintering temperatures. When the sintering temperature increased from 1400 to 1500 °C, the samples shrunk increasingly and the porosity decreased from 89.5 to 86.75%, which lead to the alumina foams strength increased from 0.27 MPa (at 1400 °C) to 0.627 MPa (at 1500 °C). When the sintering temperature increased from 1500 to 1550 °C, the porosity changed a little but the grains of samples grew up and contacted more tightly which resulted in the improvement of foam strength. When the sintering temperature is up to 1600 °C, a few grains preferentially grew too large compared to other grains, which caused a little decrease of strength. Therefore, to get strong alumina foams, the sintering temperature of 1550 °C was suggested in our work.