Oxidation behavior of FeAl alloys with and without titanium

摘要

The influence of Ti addition on the high temperature oxidation behavior of FeAl intermetallic alloys in air at 1000°C and 1100°C has been investigated. The oxidation kinetics of FeAl alloys was examined by the weight gain method and oxide products were examined by XRD, SEM, EDS and EPMA. The results showed that the oxidation kinetic curves of both Ti-doped and binary Fe-36.5Al alloys could be described as different parabolas that followed the formula: (ΔW/S)2 = K p t + C. The parabolic rate constant, K p values are approximately 2.4 and 3.3 mg2 cm−4 h−1 for Fe-36.5Al alloy and about 1.3 and 2.0 mg2 cm−4 h−1 for Fe-36.5Al-2Ti alloy when oxidizing at 1000°C and 1100°C respectively. The difference between Fe-36.5Al and Fe-36.5Al-2Ti alloy is not only in the surface morphology but also in the phase components. In the surface there is only α-Al2O3 oxide for Fe-36.5Al alloy while there are α-Al2O3 and TiO oxides for Fe-36.5Al-2Ti alloy. The effects of Ti addition on the oxidation resistance of FeAl alloy were addressed based on the microstructural evidence.