Fig. 1. Sampling mode of oxidation specimens in laser additive manufacturing of titanium aluminum alloys

Fig. 2. Lamellar map of TiAl alloy. (a) As-deposited lamellar colony; (b) as-casted lamellar colony; (c) inside of as-deposited lamellar colony; (d) inside of as-casted lamellar colony

Fig. 3. Surface morphology of oxide after isothermal oxidation of 60 h at 850 ℃. (a) As-deposited specimen; (b) as-casted specimen

Fig. 4. Oxidation dynamic curves of as-deposited and as-casted specimens at 850 ℃. (a) Metal oxidation weight increase before logarithm transformation; (b) metal oxidation weight increase after logarithm transformation

Fig. 5. XRD results after isothermal oxidation of 12, 36, 72 h at 850 ℃. (a) As-casted specimen; (b) as-deposited specimen

Fig. 6. Scan maps of cross section of oxidation film. (a) As-casted specimen; (b) as-deposited specimen

Fig. 7. EDS line scanning results of oxidation film of as-casted specimen after isothermal oxidation of 60 h at 850 ℃. (a) Cross-section of oxidation film; (b) Ti element; (c) Al element; (d) O element

Fig. 8. EDS line scanning results of oxidation film of as-deposited specimen after isothermal oxidation of 60 h at 850 ℃. (a) Cross-section of oxidation film; (b) Ti element; (c) Al element; (d) O element

Fig. 9. Structural diagram of oxidation film. (a) As-deposited specimen; (b) as-casted specimen