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以Cr改性的Fe3Al预合金粉末为原料,采用粉末冶金方法制备Fe3Al多孔材料,研究氧化温度、时间、降温速度对Fe3Al多孔材料氧化膜性能的影响。结果表明:Fe3Al多孔材料的氧化增重随温度的升高而增大,氧化动力学遵循四次方规律,在800℃的大气中氧化9h,氧化膜已完全将烧结颈覆盖,晶粒细小;随着温度的升高和时间的延长,晶粒变得粗大;900℃氧化5h,膜层已出现裂纹;而降温速度对氧化增重的影响不大,也没有出现由于热膨胀不匹配而产生的裂纹。
Fe3Al porous materials were prepared by Cr-modified Fe3Al pre-alloyed powders by powder metallurgy method. The effects of oxidation temperature, time and cooling rate on the properties of Fe3Al porous films were studied. The results show that the oxidation weight gain of Fe3Al porous materials increases with the increase of temperature, the oxidation kinetics follow the fourth law, and oxidizes in the atmosphere at 800 ℃ for 9h. The oxide film has completely covered the sintering neck and has fine grains. With the increase of temperature and time, the grains became coarse. The cracks occurred on the film after oxidation at 900 ℃ for 5h. However, the cooling rate had little effect on the weight gain and did not appear due to thermal expansion mismatch crack.