Enhanced properties of MgO–Al 2 O 3 composite materials with Al powder addition under 1300 °C creep test and its mechanism analysis

The Al-MgO-Al 2 O 3 composite samples were prepared with alumina (fused corundum and sintered alumina), high purity sintered magnesia and aluminum powder. Creep test was carried out at 1300 °C and studied. The results show that the creep rate of sample without aluminum addition decreases gradually. The creep properties of the MgO-Al 2 O 3 composite material are improved by aluminum powder addition, with the sample demonstrating an increase creep rate. The physical properties of the samples are enhanced by aluminum powder addition as well. The mechanism of the improvement on the sample is analyzed by different characterization methods and kinetics calculations. Our results indicates that the AlN and MgAl 2 O 4 spinel phases which are formed during the creep test are acting as the reinforcing phases and therefore enhance the creep performance of the samples.