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Microstructural Properties of Heat-Treated LENS In Situ Additively Manufactured Titanium Aluminide

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Abstract

This study reports on the microstructure, phase identification and hardness property of the LENS-manufactured binary Ti-Al alloy which was achieved via laser in situ alloying. The in situ alloying method, using laser beam as an energy source, indicated that it is possible to achieve a binary gamma phase microstructure from elemental powders of Ti and Al. The as-produced sample, however, was characterized of having different microstructure at the top, middle and bottom regions. The middle and top layers had similar hardness which was lower than that of the bottom region. The as heat-treated sample was characterized of lamellar grain microstructure at the top and just grains at the bottom and the middle. The observed grains were different in size, phase and hardness. This study indicated that in addition to the pores and the precipitation of α2 phase or aluminum segregation on the grain boundary veins intermetallics lead to severe cracking. Overall, the hardness values of the as-produced and heat-treated samples were similar, and due to extensive cracking, it was inferred that both samples will lack ductility.

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References

  1. F. Appel, M. Oehring, and J.D.H. Paul, A Novel In Situ Composite Structure in TiAl Alloys, Mater. Sci. Eng. A, 2008, 493, p 232–236

    Article  Google Scholar 

  2. A. Clemens, A. Bartels, S. Bystrzanowski, H. Chladil, H. Leitner, G. Dehm, R. Gerling, and F.P. Schimansky, Grain Refinement in γ-TiAl Based Alloys by Solid State Phase Transformations, Intermetallics, 2006, 14, p 1380–1385

    Article  Google Scholar 

  3. A. Rostamian and A. Jacot, A Numerical Model for the Description of the Lamellar and Massive Phase Transformation in TiAl Alloys, Intermetallics, 2008, 16, p 1227–1236

    Article  Google Scholar 

  4. F. Appel, H. Clemens, and F.D. Fischer, Modeling Concepts for Intermetallic Titanium Aluminides, Prog. Mater Sci., 2016, 81, p 55–124

    Article  Google Scholar 

  5. G. Wang and M. Dahms, Synthesizing Gamma-TiAl Alloys by Reactive Powder Processing, JOM, 1993, 45, p 52–56 (in English)

    Article  Google Scholar 

  6. N.A. Nochovnaya, P.V. Panin, A.S. Kochetkov, and K.A. Bokov, Modern Refractory Alloys Based on Titanium Gamma-Aluminide: Prospects of Development and Application, Met. Sci. Heat Treat., 2014, 56(8), p 23–27

    Google Scholar 

  7. H. Clemens and S. Mayer, Design, Processing, Microstructure, Properties, and Applications of Advanced Intermetallic TiAl Alloys, Adv. Eng. Mater., 2013, 15(4), p 191–215

    Article  Google Scholar 

  8. J.D.K. Rivard, A.S. Sabau, C.A. Blue, D.C. Harper, and J.O. Kiggans, Modeling and Processing of Liquid-Phase-Sintering γ-TiAl During High-density Infrared Processsing, Metall. Mater. Trans. A, 2006, 37A, p 1289–1299

    Article  Google Scholar 

  9. M. Todai, T. Nakano, T. Liu, H.Y. Yasuda, K. Hagihara, K. Cho, M. Ueda, and M. Takeyama, Effect of Building Direction on the Microstructure and Tensile Properties of Ti-48Al-2Cr-2Nb Alloy Additively Manufactured by Electron Beam Melting, Addit. Manuf., 2017, 13, p 61–70

    Article  Google Scholar 

  10. R. Gerling, E. Aust, W. Limberg, M. Pfuff, and F.P. Schimansky, Metal Injection Moulding of gamma Titanium Aluminide Alloy Powder, Mater. Sci. Eng. A, 2006, 423, p 262–268

    Article  Google Scholar 

  11. A. Dehghan-Manshadi, D. StJohn, M. Dargusch, Y. Chen, J.F. Sun, and M. Qian, Metal Injection Moulding of Non-spherical Titanium Powders: Processing, Microstructure and Mechanical Properties, J. Manuf. Process., 2018, 31, p 416–423

    Article  Google Scholar 

  12. R. Gerling and F.P. Schimansky, Prospects for Metal Injection Moulding Using a Gamma Titanium Based Alloy Powder, Mater. Sci. Eng. A, 2002, 329-331, p 45–49

    Article  Google Scholar 

  13. A. Dehghan-Manshadi, M.J. Bermingham, M.S. Dargusch, D.H. StJohn, and M. Qian, Metal Injection Moulding of Titanium and Titanium Alloys: Challenges and Recent Development, Powder Technol., 2017, 319, p 289–301

    Article  Google Scholar 

  14. L.E. Murr, Metallurgy of Additive Manufacturing: Examples from Electron Beam Melting, Addit. Manuf., 2015, 5, p 40–53

    Article  Google Scholar 

  15. M. Galati and L. Iuliano, A Literature Review of Powder-Based Electron Beam Melting Focusing on Numerical Simulation, Addit. Manuf., 2018, 19, p 1–20

    Article  Google Scholar 

  16. P.K. Gokuldoss, S. Kolla, and J. Eckert, Additive Manufacturing Processes: Selective Laser Melting, Electron Beam Melting and Binder Jetting-Selection Guidelines, Materials, 2017, 10(672), p 1–12

    Google Scholar 

  17. M. Tlotleng, B. Masina, and S. Pityana, Characteristics of Laser In Situ Alloyed Titanium Aluminides Coatings, Procedia Manuf., 2017, 7, p 39–45

    Article  Google Scholar 

  18. A.N.D. Gasper, S. Catchpole-Smith, and A.T. Clare, In Situ Synthesis of Titanium Aluminides by Direct Metal Deposition, J. Mater. Process. Technol., 2017, 239, p 230–239

    Article  Google Scholar 

  19. M. Thomas, T. Malot, and P. Aubry, Laser Metal Deposition of the Intermetallic TiAl Alloy, Metall. Mater. Trans. A, 2017, 48A, p 3143–3157

    Article  Google Scholar 

  20. R.M. Imaev, V.M. Imaev, and T.G. Khismatullin, Refining of the Microstructure of Cast Intermetallic Alloy Ti-43% Al-X (Nb, Mo, B) with the Help of Heat Treatment, Met. Sci. Heat Treat., 2006, 48(1-2), p 81–84

    Article  Google Scholar 

  21. Y.H. Wang, J.P. Lin, Y.H. He, X. Lu, Y.L. Wang, and G.L. Chen, Microstructure and Mechanical Properties of High Nb Containing TiAl Alloys by Reactive Hot Pressing, J. Alloys Compd., 2008, 461, p 367–372

    Article  Google Scholar 

  22. A.R.C. Sharman, J.I. Hughes, and K. Ridgway, Characterisation of Titanium Aluminide Components Manufactured by Laser Metal Deposition, Intermetallics, 2018, 93, p 89–92

    Article  Google Scholar 

  23. J. Lapin, Z. Gabalcova, and O. Bajana, The Effect of Microstructure on the Mechanical Properties of Directionally Solidified Intermetallic Ti-46Al-8Nb Alloy, Kovové Materiály, 2009, 47, p 159–167 (in English)

    Google Scholar 

  24. Y. Guangyu, J. Wenpeng, Z. Pei, J. Liang, L. Nan, W. Jian, and T. Huiping, Microstructure of As-Fabricated and Post Heat Treated Ti-47Al-2Nb-2Cr Alloy Produced by Selective Electron Beam Melting (SEBM), Rare Met. Mater. Eng., 2016, 45(7), p 1683–1686

    Article  Google Scholar 

  25. I. Shishkovsky, F. Missemer, and I. Smurov, Direct Metal Deposition of Functional Graded Structures in Ti-Al System, Phys. Procedia, 2012, 39, p 382–391

    Article  Google Scholar 

  26. K. Kothari, R. Radhakrishnan, N.M. Wereley, and T.S. Sudarshan, Microstructure and Mechanical Properties of Consolidated Gamma Titanium Aluminides, Powder Metall., 2007, 50(1), p 21–27

    Article  Google Scholar 

  27. T. Voisin, J.-P. Monchoux, M. Perrut, and A. Couret, Obtained of a Fine Near-Lamellar Microstructure in TiAl Alloys by Spark Plasma Sintering, Intermetallics, 2016, 71, p 88–97

    Article  Google Scholar 

  28. C. Mercer and W.O. Soboyejo, Hall–Patch Relationship in Gamma Titanium Aluminides, Scr. Mater., 1996, 35(1), p 17–22

    Article  Google Scholar 

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Acknowledgments

The author would like to acknowledge the financial support that was received from both The National Research Foundation and The Council for Scientific and Industrial Research. The following grants supported this research: National Research Foundation Thuthuka (Grant No. BM_TTK170905261706), CSIR Young Researcher Establishment Funds (YREF212) and CSIR Parliamentary Grant (LMIRDPP07030).

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Authors and Affiliations

  1. Additive Manufacturing Research Group, Laser Enabled Manufacturing, National Laser Centre, Council for Scientific and Industrial Research, Pretoria Campus, Pretoria, South Africa

    Monnamme Tlotleng

  2. Department of Mechanical Engineering Science, Faculty of Engineering and the Built Environment, University of Johannesburg, Auckland Park Campus, Johannesburg, South Africa

    Monnamme Tlotleng

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  1. Monnamme Tlotleng
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Correspondence to Monnamme Tlotleng.

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Tlotleng, M. Microstructural Properties of Heat-Treated LENS In Situ Additively Manufactured Titanium Aluminide. J. of Materi Eng and Perform 28, 701–708 (2019). https://doi.org/10.1007/s11665-018-3789-5

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  • DOI: https://doi.org/10.1007/s11665-018-3789-5

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