Microstructural Investigation and Phase Relationships of Fe-Al-Hf Alloys

Date

2014-4-2

Author

Yildirim, Mehmet
Akdeniz, Mahmut Vedat
Mehrabov, Amdulla

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The effect of Hf addition on microstructures, phase relationships, microhardness, and magnetic properties of Fe50Al50-n Hf (n) alloys for n = 1, 3, 5, 7, and 9 at. pct has been investigated. At all investigated compositions, the ternary intermetallic HfFe6Al6 tau (1) phase forms due to the limited solid solubility of Hf in FeAl phase and tends to develop a eutectic phase mixture with the Fe-Al-based phase. The Hf concentration of the eutectic composition is found to be 7 at. pct from the microstructural examinations and the eutectic phase transition temperature is determined as 1521 K (1248 A degrees C) independent of Hf amount by differential scanning calorimetry measurements. Furthermore, the enthalpies and activation energies (based on Kissinger and Ozawa methods) of eutectic phase transitions are reported. The minimum activation energy is calculated for the fully eutectic composition. Moreover, variation of the microhardness of Fe-Al-based alloys as a function of the Hf content is investigated, and its dependence on the thermal history of the alloys is explained.

Subject Keywords

Iron-aluminum-alloys, Mechanical-properties, High-strength, Intermetallic alloys, Laves phase, Deformation, Temperature, Composite, Behavior, Transformation

URI

https://hdl.handle.net/11511/28224

Journal

Metallurgical and Materials Transactions A

DOI

https://doi.org/10.1007/s11661-014-2287-0

Collections

Department of Metallurgical and Materials Engineering, Article

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Citation Formats

M. Yildirim, M. V. Akdeniz, and A. Mehrabov, “Microstructural Investigation and Phase Relationships of Fe-Al-Hf Alloys,” Metallurgical and Materials Transactions A, pp. 3412–3421, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/28224.