Effect of Moiar Ratio of Al_2O_3 to Fe_2O_3 on the Sintering and Thermal Shock Resistance of Al_2O_3-Fe_2O_3 Composite

摘要

The Al_2O_3-Fe_2O_3 composite was prepared at 1550°C for 3h with alumina powder and ferric oxide powder as raw materials and with magnesia powder as additive. The effect of molar ratio of Al_2O_3 to Fe_2O_3 on the sintering and thermal shock resistance of the composite materials was studied. The results showed that the apparent porosity and bulk density of the samples both decreased with the molar ratio of Al_2O_3 to Fe_2O_3 increase, as a result, the linear change ratio and bending strength both increased. When the molar ratio of Al_2O_3 to Fe_2O_3 equals to 3, the sample exhibits excellent thermal shock resistance. The XRD and SEM analysis results indicated that the mechanical and thermal proprieties are relative to the microstructure and crystal phases of the composite materials.