Founding Research Journal

Founding Research Journal

Investigation and Determining the Temperature of the α2 to α Transformation During Hot Deformation of Ti-48Al-2Cr-2Nb Intermetallic

Document Type : Original Research Article

Authors
Hossein Rezaei 1
Maryam Morakabati 2
Amir Momeni 3
1 PhD Student in Materials Engineering, Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran
2 Associate Professor, Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran
3 Associate Professor, Faculty of Metallurgy and Material Engineering, Hamedan University of Technology, Hamedan, Iran
10.22034/frj.2025.481523.1201
Abstract
The aim of the present study is to investigate the occurrence of the α2 to α phase transformation during hot compressive deformation of Ti-48Al-2Cr-2Nb intermetallic. To this end, hot compression tests were performed on samples of the intermetallic at temperatures of 1000, 1050, 1100, and 1150°C, with a constant strain rate of 0.01 s⁻¹. After hot deformation at 1000 and 1050°C, tall peaks of the γ phase, along with relatively shorter peaks of the α2 phase, were observed in the X-ray diffraction analysis results. With the increase in deformation temperature to 1100 and 1150°C, the α2 phase peaks disappeared, and peaks of the α phase emerged. After hot deformation at 1000 and 1050°C, bent and broken lamellae, along with some recrystallized grains, were observed in the microstructure. However, with the increase in hot deformation temperature to 1100°C, the onset of transformation led to the decomposition of the α2 phase, creating decomposed regions rich in the γ phase, thus increasing the amount of this phase in the microstructure. Therefore, based on the above results, it can be concluded that the ordering transformation begins in the temperature range of 1050 to 1100°C and completes in the range of 1100 to 1150°C.
Keywords
Ti-48Al-2Cr-2Nb Intermetallic
&‌alpha
2/&‌alpha
Transformation
Bending Lamellae
Recrystallization
Subjects
[1] Clemens H. and Mayer S., Advanced intermetallic TiAl alloys. Materials Science Forum, 2017, 879, 113-118.
[2] Bewlay B.P., et al., TiAl alloys in commercial aircraft engines, Materials at High Temperatures, 2016, 33, 549-559.
[3] Kothari K., Radhakrishnan R., Wereley N.M., Advances in gamma titanium aluminides and their manufacturing techniques, Progress in Aerospace Sciences, 2012, 55, 1-16.
[4] Chen Y.Y., et al., Research on the hot precision processing of TiAl alloys, Materials Science Forum, 2009, 620, 407-412.
[5] Lapin J., TiAl-based alloys: Present status and future perspectives, in Metals, 2009: Hradec nad Moravicí.
[6] Paul J.D.H., Appel F., Work-hardening and recovery mechanisms in gamma-based titanium aluminides, Metall Mater Trans A 2003, 34, 2103-2111.
[7] Chen X., et al., Dynamic recrystallization behavior of the Ti–48Al–2Cr–2Nb alloy during isothermal hot deformation, Progress in Natural Science: Materials International, 2019, 29, 587-594.
[8] Shih D., Scarr G., High-Temperature deformation behavior of the γ alloy Ti-48Ai-2Cr-2Nb, MRS Online Proceedings Library, 1990, 213, 727-732.
[9] Usta M., et al., Thermo-mechanical grain refinement in gamma (g) based TiAl intermetallics, Materials Science and Engineering: A, 2003, 359, 168-177.
[10] Tian S., et al., Investigation on the microstructure evolution and dynamic recrystallization mechanisms of TiAl alloy at elevated temperature, Journal of Materials Research and Technology, 2021, 14, 968-984.
[11] Wang Y., et al., Grain refinement of a TiAl alloy by heat treatment through near gamma transformation, Journal Of Materials Science, 2001, 36, 4465 – 4468.
[12] Zhang S.Z., et al., Phase transformation and microstructure evolution of differently processed Ti-45Al-9Nb-Y alloy, Intermetallics, 2012, 31, 208-216.
[13] Voort, G.F.V., Handbook metallography and microstructurs Vol. 9, 2004, USA: ASM International.
[14] Li B.H., et al., Microstructure and mechanical properties of as-cast Ti–43Al–9V–0.3Y alloy, Journal of Alloys and Compounds, 2009, 473(1-2), 123-126.
[15] Tan Y., et al., Effect of solution heat treatment on the microstructure and hardness of theTi-48Al-2Cr-2Nb alloy prepared by electron beam smelting, Journal of Materials Engineering and Performance, 2021, 31, 1387–1396.
[16] Duan B., et al., History and development of γ-TiAl alloys and the effect of alloying elements on their phase transformations, Journal of Alloys and Compounds, 2022, 909.
[17] Genc O., Ünal R., Development of gamma titanium aluminide (γ-TiAl) alloys: A Review, Journal of Alloys and Compounds, 2022, 929.
[18] Appel F., et al., Recent progress in the development of gamma titanium aluminide alloys, Advance Engineering Materials, 2000, 3, 699-720.
[19] Baker I., Recovery, recrystallization and grain growth in ordered alloys, Intermetallics, 2000, 8(9-11) 1183-1196.
[20] Hu Q., et al., Hot deformation behavior and dynamic recrystallization mechanism of Ti-48Al-2Nb-2Cr alloy with near-γ microstructure, Journal of Alloys and Compounds, 2023, 945.
[21] Appel F., Mechanistic understanding of creep in gamma-base titanium aluminide alloys, Intermetallics, 2001, 9(10-11) 907-914.
[22] Appel F., Diffusion assisted dislocation climb in intermetallic gamma TiAl, Materials Science and Engineering: A, 2001, 317(1-2) 115-127.
Founding Research Journal
Volume 9, Issue 2 - Serial Number 27
Autumn and Winter
Autumn 2025
Pages 85-91

  • Receive Date 02 October 2024
  • Revise Date 05 May 2025
  • Accept Date 01 June 2025