[1] Y.W. Kim, Ordered intermetallic alloys, part III: gamma titanium aluminides, JOM 46 (1994) 30–39, https://doi.org/10.1007/BF03220745.
[2] P. Bartolotta, J. Barrett, T. Kelly, R. Smashey, The use of cast Ti–48Al–2Cr–2Nb in jet engines, JOM 49 (1997) 48–50, https://doi.org/10.1007/BF02914685.
[3] J. Aguilar, A. Schievenbusch, O. K¨attlitz, Investment casting technology for production of TiAl low pressure turbine blades – Process engineering and parameter analysis, intermetallics 19 (2011) 757–761, https://doi.org/10.1016/j. intermet.2010.11.014.
[4] B.P. Bewlay, S. Nag, A. Suzuki, M.J. Weimer, TiAl alloys in commercial aircraft engines, Mater. High. Temp. 33 (2016) 549–559, https://doi.org/10.1080/09603409.2016.1183068.
[5] M. Takeyama, S. Kobayashi, Physical metallurgy for wrought gamma titanium aluminides: microstructure control through phase transformations, Intermetallics 13 (2005) 993–999, https://doi.org/10.1016/j.intermet.2004.12.014.
[6] T. Tetsui, K. Shindo, S. Kobayashi, M. Takeyama, A newly developed hot worked TiAl alloy for blades and structural components, Scr. Mater. 47 (2002) 399–403, https://doi.org/10.1016/S1359-6462(02)00158-6.
[7] A. Shaaban, H. Wakabayashi, H. Nakashima, M. Takeyama, Phase equilibria among β/α/α2/γ phases and phase transformations in Ti–Al–Cr system at elevated temperatures, Process. Manuf. 4 (2019) 1471–1476, https://doi.org/10.1557/ adv.2019.111.
[8] H. Clemens, W. Wallgram, S. Kremmer, V. Güther, A. Otto, A. Bartels, Design of novel β-solidifying TiAl alloys with adjustable β/B2-phase fraction and excellent hot-workability, Adv. Eng. Mater. 10 (2008) 707–713, https://doi.org/10.1002/ adem.200800164.
[9] M.T. Jovanovi´c, B. Dimˇci´c, I. Bobi´c, S. Zec, V. Maksimovi´c, Microstructure and mechanical properties of precision cast TiAl turbocharger wheel, J. Mater. Process. Technol. 167 (2005) 14–21, https://doi.org/10.1016/j.jmatprotec.2005.03.019.
[10] M. Yamaguchi, High temperature intermetallics – with particular emphasis on TiAl, Mater. Sci. Technol. 8 (1992) 299–307, https://doi.org/10.1179/ mst.1992.8.4.299.
[11] C. Renjie, G. Ming, Z. Hu, G. Shengkai, Interactions between TiAl alloys and yttria refractory material in casting process, J. Mater. Process. Technol. 210 (2010) 1190–1196, https://doi.org/10.1016/j.jmatprotec.2010.03.003.
[12] L. Nickels, AM and aerospace: an ideal combination, Met. Powder Rep. 70 (2015) 300–303, https://doi.org/10.1016/j.mprp.2015.06.005.
[13] T. Nakano, W. Fujitani, T. Ishimoto, J.W. Lee, N. Ikeo, H. Fukuda, K. Kuramoto, Formation of new bone with preferentially oriented biological apatite crystals using a novel cylindrical implant containing anisotropic open pores fabricated by the electron beam melting (EBM) method, ISIJ Int. 51 (2011) 262–268, https://doi. org/10.2355/isijinternational.51.262.
[14] T. Ishimoto, R. Ozasa, K. Nakano, M. Weinmann, C. Schnitter, M. Stenzel,A. Matsugaki, T. Nagasea, T. Matsuzaka, M. Todai, H.S. Kim, T. Nakano, Development of TiNbTaZrMo bio-high entropy alloy (BioHEA) super-solid solution by selective laser melting, and its improved mechanical property and biocompatibility, Scr. Mater. 194 (2021), 113658, https://doi.org/10.1016/j. scriptamat.2020.113658.
[15] N. Hrabe, T. Quinn, Effects of processing on microstructure and mechanical properties of a titanium alloy (Ti-6Al-4V) fabricated using electron beam melting (EBM), part 2: energy input, orientation, and location, Mater. Sci. Eng. A 573 (2013) 271–277, https://doi.org/10.1016/j.msea.2013.02.065.
[16] N. Ikeo, T. Ishimoto, T. Nakano, Novel powder/solid composites possessing low Young’s modulus and tunable energy absorption capacity, fabricated by electron beam melting, for biomedical applications, J. Alloy. Compd. 639 (2015) 336–340, https://doi.org/10.1016/j.jallcom.2015.03.141.
[17] S.H. Sun, Y. Koizumi, S. Kurosu, Y.P. Li, H. Matsumoto, A. Chiba, Build direction dependence of microstructure and high-temperature tensile property of Co–Cr–Mo alloy fabricated by electron beam melting, Acta Mater. 64 (2014) 154–168, https://doi.org/10.1016/j.actamat.2013.10.017.
[18] X.P. Tan, P. Wang, Y. Kok, W.Q. Toh, Z. Sun, S.M.L. Nai, M. Descoins,D. Mangelinck, E. Liu, S.B. Tor, Carbide precipitation characteristics in additive manufacturing of Co–Cr–Mo alloy via selective election beam melting, Scr. Mater. 143 (2018) 117–121, https://doi.org/10.1016/j.scriptamat.2017.09.022.
[19] L.E. Murr, E. Martinez, S.M. Gaytan, D.A. Ramirez, B.I. MacHado, P.W. Shindo, J.L. Martinez, F. Medina, J. Wooten, D. Ciscel, U. Ackelid, R.B. Wicker, Microstructural architecture, microstructures, and mechanical properties for a nickel-base superalloy fabricated by electron beam melting, Metall. Mater. Trans. A 42 (2011) 3491–3508, https://doi.org/10.1007/s11661-011-0748-2.
[20] E. Chauvet, P. Kontis, W.A. Ja¨gle, B. Gault, D. Raabe, C. Tassin, J.J. Blandin,R. Dendievel, B. Vayre, S. Abed, G. Martin, Hot cracking mechanism affecting a non-weldable Ni-based superalloy produced by selective electron beam melting, Acta Mater. 142 (2018) 82–94, https://doi.org/10.1016/j.actamat.2017.09.047.
[21] P. Wang, P. Huang, F.L. Ng, W.J. Sin, S. Lu, M.L.S. Nai, Z.L. Dong, J. Wei,Additively manufactured CoCrFeNiMn high-entropy alloy viapre-alloyed powder, Mater. Des. 168 (2019), 107576, https://doi.org/10.1016/j.matdes.2018.107576.
[22] K. Kuwabara, H. Shiratori, T. Fujieda, K. Yamanaka, Y. Koizumi, A. Chiba, Mechanical and corrosion properties of AlCoCrFeNi high-entropy alloy fabricated with selective electron beam melting, Addit. Manuf. 23 (2018) 264–271, https:// doi.org/10.1016/j.addma.2018.06.006.
[23] D. Riedlbauer, T. Scharowsky, R.F. Singer, P. Steinmann, C. Ko¨rner, J. Mergheim, Macroscopic simulation and experimental measurement of melt pool characteristics in selective electron beam melting of Ti–6Al–4V, Int J. Adv. Manuf. Technol. 88 (2017) 1309–1317, https://doi.org/10.1007/s00170-016-8819-6.
[24] W. Kan, B. Chen, H. Peng, Y. Liang, J. Lin, Formation of columnar lamellar colony grain structure in a high Nb–Ti–Al alloy by electron beam melting, J. Alloy. Compd. 809 (2019), 151673, https://doi.org/10.1016/j.jallcom.2019.151673.
[25] P. Karimia, E. Sadeghi, J. Ålgårdha, J. Andersson, EBM-manufactured single tracks of Alloy 718: influence of energy input and focus offset on geometrical and microstructural characteristics, Mater. Charact. 148 (2019) 88–99, https://doi. org/10.1016/j.matchar.2018.11.033.
[26] J. Schwerdtfeger, C. Ko¨rner, Selective electron beam melting of Ti–48Al–2Nb–2Cr: microstructure and aluminium loss, Intermetallics 49 (2014) 29–35, https://doi. org/10.1016/j.intermet.2014.01.004.
[27] L.E. Murr, S.M. Gaytan, A. Ceylan, E. Martinez, J.L. Martinez, D.H. Hernandez, B.I. Machado, D.A. Ramirez, F. Medina, S. Collins, R.B. Wicker, Characterization of titanium aluminide alloy components fabricated by additive manufacturing using electron beam melting, Acta Mater. 58 (2010) 1887–1894, https://doi.org/ 10.1016/j.actamat.2009.11.032.
[28] A.A. Abdulrahman, A. Mohammad, A. Abdullah, A. Basem, A. Abdulrahman,D. Abdelnaser, Predicting surface quality of γ-TiAl produced by additive manufacturing process using response surface method, J. Mech. Sci. Technol. 30 (2016) 345–352, https://doi.org/10.1007/s12206-015-1239-y.
[29] A. Mohammad, A.M. Alahmari, M.K. Mohammed, R.K. Renganayagalu,K. Moiduddin, Effect of energy input on microstructure and mechanical properties of titanium aluminide alloy fabricated by the additive manufacturing process of electron beam melting, Materials 10 (2017) 211, https://doi.org/10.3390/ ma10020211.
[30] Y. Chen, H. Yue, X. Wang, S. Xiao, F. Kong, X. Cheng, H. Peng, Selective electron beam melting of TiAl alloy: microstructure evolution, phase transformation and microhardness, Mater. Charact. 142 (2018) 584–592, https://doi.org/10.1016/j. matchar.2018.06.027.
[31] H. Yue, Y. Chen, X. Wang, F. Kong, Effect of beam current on microstructure, phase, grain characteristic and mechanical properties of Ti–47Al–2Cr–2Nb alloy fabricated by selective electron beam melting, J. Alloy. Compd. 750 (2018) 617–625, https://doi.org/10.1016/j.jallcom.2018.03.343.
[32] Y.K. Kim, S.J. Youn, S.W. Kim, J. Hong, K.A. Lee, High-temperature creep behavior of gamma Ti–48Al–2Cr–2Nb alloy additively manufactured by electron beam melting, Mater. Sci. Eng.: A 763 (2019), 138138, https://doi.org/10.1016/j. msea.2019.138138.
[33] M. Todai, T. Nakano, T. Liu, H.Y. Yasuda, K. Hagihara, K. Cho, M. Ueda,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. 13 (2017) 61–70, https://doi.org/10.1016/j. addma.2016.11.001.
[34] K. Cho, R. Kobayashi, J.Y. Oh, H.Y. Yasuda, M. Todai, T. Nakano, A. Ikeda,M. Ueda, M. Takeyama, Influence of unique layered microstructure on fatigue properties of Ti–48Al–2Cr–2Nb alloys fabricated by electron beam melting, Intermetallics 95 (2018) 1–10, https://doi.org/10.1016/j.intermet.2018.01.009.
[35] K. Cho, R. Kobayashi, T. Fukuoka, J.Y. Oh, H.Y. Yasuda, M. Todai, T. Nakano,A. Ikeda, M. Ueda, M. Takeyama, Microstructure and fatigue properties of TiAl with unique layered microstructure fabricated by electron beam melting, Mater.Sci. Forum 941 (2018) 1597–1602. 〈https://www.scientific.net/MSF.941.1597〉.
[36] M. Sakata, J.Y. Oh, K. Cho, H.Y. Yasuda, M. Todai, T. Nakano, A. Ikeda, M. Ueda,M. Takeyama, Effects of heat treatment on unique layered microstructure and tensile properties of TiAl fabricated by electron beam melting, Mater. Sci. Forum 941 (2018) 1366–1371. 〈https://www.scientific.net/MSF.941.1366〉.
[37] R. Wartbichler, H. Clemens, S. Mayer, Electron beam melting of a β-solidifying intermetallic titanium aluminide alloy, Adv. Eng. Mater. 21 (2019), 1900800, https://doi.org/10.1002/adem.201900800.
[38] P.L. Narayana, C.L. Li, S.W. Kim, S.E. Kim, A. Marquardt, C. Leyens, N.S. Reddy, J.T. Yeom, J.K. Hong, High strength and ductility of electron beam melted β stabilized γ-TiAl alloy at 800 ◦C, Mater. Sci. Eng. A 756 (2019) 41–45, https://doi. org/10.1016/j.msea.2019.03.114.
[39] E. Cox, A method of assigning numerical and percentage values to the degree of roundness of sand grains, J. Paleontol. 1 (1927) 179–183.
[40] Y.Y. Sun, Gulizia, C.H. Oh, C. Doblin, Y.F. Yang, M. Qian, Manipulation and characterization of a novel titanium powder precursor for additive manufacturing applications, JOM 67 (2015) 564–752, https://doi.org/10.1007/s11837-015-1301-3.
[41] S. Biamino, A. Penna, U. Ackelid, S. Sabbadini, O. Tassa, P. Fino, M. Pavese,P. Gennaro, C. Badini, Electron beam melting of Ti–48Al–2Cr–2Nb alloy: Microstructure and mechanical properties investigation, Intermetallics 19 (2011) 776–781, https://doi.org/10.1016/j.intermet.2010.11.017.
[42] Y. Zhao, K. Aoyagi, K. Yamanaka, A. Chiba, Role of operating and environmental conditions in determining molten pool dynamics during electron beam melting and selective laser melting, Addit. Manuf. (2019), 101559, https://doi.org/10.1016/j. addma.2020.101559.
[43] J. Han, J. Dong, S. Zhang, C. Zhang, S. Xiao, Y. Chen, Microstructure evolution and tensile properties of conventional cast TiAl based alloy with trace Ni addition, Mater. Sci. Eng. A 715 (2018) 41–48, https://doi.org/10.1016/j. msea.2017.12.092.
[44] J. Yang, Z. Gao, X. Zhang, R. Hu, Continuous-cooling-transformation (CCT) behaviors and fine-grained nearly lamellar (FGNL) microstructure formation in a cast Ti–48Al–4Nb–2Cr alloy, Metall. Mater. Trans. A 51 (2020) 5285–5295, https://doi.org/10.1007/s11661-020-05934-7.
[45] E. Schwaighofer, H. Clemens, S. Mayer, J. Lindemann, J. Klose, W. Smarsly,V. Güther, Microstructural design and mechanical properties of a cast and heat- treated intermetallic multi-phase γ-TiAl based alloy, Intermetallics 44 (2014) 128–140, https://doi.org/10.1016/j.intermet.2013.09.010.
[46] L.J. Signori, T. Nakamura, Y. Okada, R. Yamagata, H. Nakashima, M. Takeyama, Fatigue crack growth behavior of wrought γ-based TiAl alloy containing β-phase, Intermetallics 100 (2018) 77–87, https://doi.org/10.1016/j. intermet.2018.04.024.
[47] M.A. Morris, Dislocation configurations in two phase TiAl alloys. I. Annealed and indented structures, Philos. Mag. A 68 (1993) 237–257, https://doi.org/10.1080/01418619308221203.
[48] H. Inui, K. Kishida, M. Misaki, M. Kobayashi, Y. Shirai, M. Yamaguchi, Temperature dependence of yield stress, tensile elongation and deformation structures in polysynthetically twinned crystals of Ti–Al, Philos. Mag. A 72 (1995) 1609–1631, https://doi.org/10.1080/01418619508243933.
[49] H.Y. Yasuda, T. Nakano, Y. Umakoshi, The deformation substructure in cyclically deformed TiAl PST crystals, Philos. Mag. A 73 (1996) 1035–1051, https://doi.org/ 10.1080/01418619608243702.
[50] T. Nakano, H. Biermann, M. Riemer, H. Mughrabi, Y. Nakai, Y. Umakoshi, Classification of γ-γ and γ-α2 lamellar boundaries on the basis of continuity of strains and slip-twinning planes in fatigued TiAl polysynthetically twinned crystals, Philos. Mag. A 81 (2001) 1447–1471, https://doi.org/10.1080/014186100100021618.
[51] M. Schloffer, B. Rashkova, T. Scho¨berl, E. Schwaighofer, Z. Zhang, H. Clemens,S. Mayer, Evolution of the ωo phase in a β-stabilized multi-phase TiAl alloy and its effect on hardness, Acta Mater. 64 (2014) 241–252, https://doi.org/10.1016/j. actamat.2013.10.036.
[52] X. Wang, J. Yang, K. Zhang, R. Hu, L. Song, H. Fu, Atomic-scale observations of B2→ ω-related phases transition in high-Nb containing TiAl alloy, Mater. Charact. 130 (2017) 135–138, https://doi.org/10.1016/j.matchar.2017.06.003.
[53] T.B. Massalski, Massive transformations revisited, Metall. Mater. Trans. A 33 (2002) 2277–2283, https://doi.org/10.1007/s11661-002-0351-7.
[54] M. Kastenhuber, T. Klein, B. Rashkova, I. Weißensteiner, H. Clemens, S. Mayer, Phase transformations in a β-solidifying γ-TiAl based alloy during rapid solidification, Intermetallics 91 (2017) 100–109, https://doi.org/10.1016/j. intermet.2017.08.017.
[55] Z.C. Liu, J.P. Lin, S.J. Li, G.L. Chen, Effects of Nb and Al on the microstructures and mechanical properties of high Nb containing TiAl base alloys, Intermetallics 10 (2002) 653–659, https://doi.org/10.1016/S0966-9795(02)00037-7.
[56] Y. Umakoshi, T. Nakano, The role of ordered domains and slip mode of α2 phase in the plastic behaviour of TiAl crystals containing oriented lamellae, Acta Metall. Mater. 41 (1993) 1155–1161, https://doi.org/10.1016/0956-7151(93)90163-M.
[57] Y.Q. Yan, Z.Q. Zhang, G.Z. Luo, K.G. Wang, L. Zhou, Microstructures observation and hot compressing tests of TiAl based alloy containing high Nb, Mater. Sci. Eng. A 280 (2000) 187–191, https://doi.org/10.1016/S0921-5093(99)00664-4.