Research on the Preoxidation Performance of Fe3Al Porous Materials

Abstract:

Fe3Al porous materials were fabricated by the powder metallurgy method with Cr-modified Fe3Al pre-alloy powder as starting material. The effects of oxidation temperature and time, and cooling rate on properties of oxidation scales of Fe3Al porous materials were researched. The results show that oxidation mass gain is increased with the temperature increasing. Oxidation kinetics of Fe3Al porous materials follows the fourth power rules. The oxidation scales with small grain size have completely covered the sintered neck of Fe3Al porous materials after 9 h oxidation in atmosphere at 800 oC. The grains become coarse with higher temperature and longer time. The cracks have appeared on oxidation scales after 5 h oxidation in atmosphere at 900 oC. Cooling rate has little effect on mass gain and the cracks do not appear due to the unmatched thermal expansion coefficient.