The Influence of Niobium Additions on Creep Resistance of Fe-27 at. % Al Alloys
Abstract
:1. Introduction
2. Materials and Methods
3. Results
4. Discussion
- (i)
- At higher temperatures and lower stresses, the creep resistance of the 10% niobium alloy is higher than that of the lower niobium alloys. At a temperature of 850 °C, the creep resistance of the alloy with 10% of niobium is the best over the entire stress range studied.
- (ii)
- This effect is reversed at lower temperatures and higher stresses. At a temperature of 650 °C and stresses higher than 200 MPa, the 5% niobium alloy has the highest creep resistance.
5. Conclusions
- The studied range of temperatures could be divided into two areas: below and above 700 °C. This division follows the existence of different crystal lattices at lower and higher temperatures.
- The stress exponent n decreases with increasing temperature at temperatures up to 700 °C and increases at higher temperatures.
- The apparent activation energy of the creep is close to 335 kJ/mol and is comparable to the activation enthalpy of niobium diffusion in Fe(Al).
- At higher temperatures and lower stresses, the creep resistance of both alloys is worse than that of a 10% niobium eutectic alloy.
- At a temperature of 650 °C and stresses higher than 200 MPa, the 5% niobium alloy has the best creep resistance.
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Alloy | Fe | Al | Nb |
---|---|---|---|
FA3Nb | 71.5 | 25.8 | 2.7 |
FA5Nb | 67.9 | 27.3 | 4.8 |
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Dobeš, F.; Dymáček, P.; Friák, M. The Influence of Niobium Additions on Creep Resistance of Fe-27 at. % Al Alloys. Metals 2019, 9, 739. https://doi.org/10.3390/met9070739
Dobeš F, Dymáček P, Friák M. The Influence of Niobium Additions on Creep Resistance of Fe-27 at. % Al Alloys. Metals. 2019; 9(7):739. https://doi.org/10.3390/met9070739
Chicago/Turabian StyleDobeš, Ferdinand, Petr Dymáček, and Martin Friák. 2019. "The Influence of Niobium Additions on Creep Resistance of Fe-27 at. % Al Alloys" Metals 9, no. 7: 739. https://doi.org/10.3390/met9070739