Effect of Cr, Nb, Mn, V, W and Si on high temperature oxidation of TiAl alloys

Lee, Dong Bok

doi:10.1007/bf03027458

Cited by 48 publications

(9 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of V-rich oxides and subsequent evaporation is reported to be a common reason for significant deterioration of scale adherence in TiAl-based alloys [46,47,48,49,50]; however, this effect is generally observed at T ≥ 700 °C. It should be noted that the decrease in the quantity and intensity of the V 2 O 5 oxide diffraction peaks after testing of the AlNbTiVZr 0.25 alloy at 700 °C can be an indication of its partial evaporation that likely activates the breakaway oxidation at this temperature.…”

Section: Discussionmentioning

confidence: 99%

Oxidation Behavior of Refractory AlNbTiVZr0.25 High-Entropy Alloy

et al. 2018

View full text Add to dashboard Cite

Oxidation behavior of a refractory AlNbTiVZr0.25 high-entropy alloy at 600–900 °C was investigated. At 600–700 °C, two-stage oxidation kinetics was found: Nearly parabolic oxidation (n = 0.46–0.48) at the first stage, transitioned to breakaway oxidation (n = 0.75–0.72) at the second stage. At 800 °C, the oxidation kinetics was nearly linear (n = 0.92) throughout the entire duration of testing. At 900 °C, the specimen disintegrated after 50 h of testing. The specific mass gains were estimated to be 7.2, 38.1, and 107.5, and 225.5 mg/cm2 at 600, 700, and 800 °C for 100 h, and 900 °C for 50 h, respectively. Phase compositions and morphology of the oxide scales were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was shown that the surface layer at 600 °C consisted of the V2O5, VO2, TiO2, Nb2O5, and TiNb2O7 oxides. Meanwhile, the scale at 900 °C comprised of complex TiNb2O7, AlNbO4, and Nb2Zr6O17 oxides. The oxidation mechanisms operating at different temperatures were discussed and a comparison of oxidation characteristics with the other alloys was conducted.

show abstract

Section: Discussionmentioning

confidence: 99%

Oxidation Behavior of Refractory AlNbTiVZr0.25 High-Entropy Alloy

et al. 2018

View full text Add to dashboard Cite

show abstract

“…However, the application of TiAl alloys is limited by their insufficient oxidation resistance at high temperatures (above 800°C). Alloying elements have been proposed to improve oxidation resistance at high temperatures, for example, V, Cr, Mn, and Nb (Lee, 2005;Vojtech et al, 2011;Raji et al, 2020). Excessive alloying may degrade the mechanical properties of the alloys.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Oxidation Behavior of NiCoCrAlY Coating With Different Sm2O3 Concentration on TiAl Alloy

et al. 2021

View full text Add to dashboard Cite

In order to improve the oxidation resistance of TiAl alloys, NiCoCrAlY coatings with different amounts of Sm2O3 were prepared by laser cladding on TiAl alloys. The microstructure and oxidation behavior of the coatings were investigated by isothermal oxidation tests at 900°C. The results indicated that the grains of the coatings were refined by Sm2O3. The fine grain reduced the crack sensitivity of the doped coatings and promoted the transformation of θ-Al2O3 to α-Al2O3. Therefore, the internal oxidation of the coatings and the growth rate of the oxide films were reduced. The segregation of Sm at grain boundary inhibited the outward diffusion of Ti, thus reducing the excessive oxidation of Ti. In addition, the oxidation mechanism of the coating was changed from simultaneous diffusion of Al and O to predominant inward diffusion of O. The oxidation resistance of the doped coatings was significantly improved. However, excessive Sm2O3 is detrimental to the improvement of the oxidation resistance. The oxidation resistance of 3 wt% Sm2O3 is the best.

show abstract

“…A uniform dense Al 2 O 3 layer is key to improving the oxidation resistance of TiAl alloys. However, the Al 2 O 3 layer formed in the high-V-containing TiAl alloy is thin and discontinuous [13,14]. A high Nb content limits the hot deformability of alloys due to the weak β stability of Nb.…”

Section: Introductionmentioning

confidence: 99%

Hot Deformation Behavior and Microstructural Evolution of a Novel β-Solidifying Ti–43Al–3Mn–2Nb–0.1Y Alloy

Cui

Xiao

et al. 2019

Materials

View full text Add to dashboard Cite

In this paper, the hot deformability and mechanical properties of a novel Mn- and Nb- containing TiAl alloy were studied systematically with the use of isothermal compression experiments. The results show that the alloy has low deformation resistance and a low activation energy (392 KJ/mol), suggesting that the alloy has good hot deformability. A processing map was established, which shows that the present alloy has a smaller instability region and wider hot working window compared with other TiAl alloys. Microstructural observation shows that the initial lamellae completely transformed into fine equiaxial γ grains when the alloy was compressed at 1200 °C/0.01 s−1, which corresponds to the optimum deformation condition. Based on the above results, an intact TiAl billet was successfully fabricated by one-step large deformation using a four-column hydraulic machine. The microstructure of the billet is almost completely composed of recrystallized γ grains with large angle boundaries. Tensile testing shows the billet exhibits high tensile strength (780 MPa) and high elongation (1.44%) simultaneously, which benefits from fine γ grains with an average size of 4.9 μm. The ductile–brittle transition temperature is between 750–800 °C.

show abstract

Effect of Cr, Nb, Mn, V, W and Si on high temperature oxidation of TiAl alloys

Cited by 48 publications

References 16 publications

Oxidation Behavior of Refractory AlNbTiVZr0.25 High-Entropy Alloy

Oxidation Behavior of Refractory AlNbTiVZr0.25 High-Entropy Alloy

Microstructure and Oxidation Behavior of NiCoCrAlY Coating With Different Sm2O3 Concentration on TiAl Alloy

Hot Deformation Behavior and Microstructural Evolution of a Novel β-Solidifying Ti–43Al–3Mn–2Nb–0.1Y Alloy

Contact Info

Product

Resources

About