Abstract
Two ternary TiAl-based alloys with chemical compositions of Ti-46.4 at. pct Al-1.4 at. pct Si (Si poor) and Ti-45 at. pct Al-2.7 at. pct Si (Si rich), which were prepared by reaction powder processing, have been investigated. Both alloys consist of the intermetallic compounds y-TiAl, α2-Ti3Al, and ξ-Ti5(Si, Al)3. The microstructure can be described as a duplex structure(i.e., lamellar γ/α2 regions distributed in γ matrix) containing ξ precipitates. The higher Si content leads to a larger amount of ξ precipitates and a finer y grain size in the Si-rich alloy. The tensile properties of both alloys depend on test temperature. At room temperature and 700 °C, the tensile properties of the Si-poor alloy are better than those of the Si-rich alloy. At 900 °C, the opposite is true. Examinations of tensile deformed specimens reveal ξ-Ti5(Si, Al)3 particle debonding and particle cracking at lower test temperatures. At 900 °C, nucleation of voids and microcracks along lamellar grain boundaries and evidence for recovery and dynamic recrystallization were observed. Due to these processes, the alloys can tolerate ξ-Ti5(Si, Al)3 particles at high temperature, where the positive effect of grain refinement on both strength and ductility can be utilized.
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References
Y.-W. Kim:JOM, 1989, July, pp. 24 M. DAHMS -28.
Y.-W. Kim and D.M. Dimiduk:JOM, 1991, Aug., pp. 40-47.
Y.-W. Kim:Acta Metall. Maler., 1992, vol. 40 (6), pp. 1121–34.
S.C. Huang and E.L. Hall:Metall. Trans. A, 1991, vol. 22A, pp. 427–39.
S.C. Huang and E.L. Hall:Metall. Trans. A, 1991, vol. 22A, pp. 2619–27.
S.C. Huang and E.L. Hall:Acta Metall. Mater., 1991, vol. 39 (6), pp. 1053–60.
W. Wunderlich, T. Kremser, and G. Frommeyer:Z. Metallkd., 1990, pp. 802-08.
M. Dahms:Mater. Sci. Eng. A, 1989, vol. 110, L5-L8.
G.-X. Wang and M. Dahms:Powder Metall. Int., 1992, vol. 24 (4), pp. 219–25.
S. Mitao and S. Tsuyama:Proc. 2nd Jpn. Int. SAMPE Symp., 1991, pp. 410-417.
Y.S. Yang and S.K. Wu:Scripta Metall. Mater., 1990, vol. 24, pp. 1801–06.
H. Inui, M.H. Oh, A. Nakamura, and M. Yamaguchi:Phil. Mag. A, 1992, vol. 66 (4), pp. 539–55.
M. Es-Souni, R. Wagner, and P.A. Beaven:Mater. Sci. Eng., 1992, vol. A151, pp. 69M-75M.
K. Shibue:Sumitomo Light Metal Technical Reports, 1991, vol. 32 (2), pp. 95–101.
G.-X. Wang and M. Dahms:Metall. Trans. A, 1993, vol. 24A, pp. 1517–26.
B. Dogan, G.-X. Wang, and M. Dahms:Scripta Metall. Mater., 1993, vol. 29, pp. 943–48.
H.A. Lipsitt, D. Schechtman, and R.E. Schafrik:Metall. Trans. A, 1975, vol. 6, pp. 1991–96.
C. Tönnes, J. Rösier, and M. Thumann:Proc. Materials by Powder Technology PTM 93, F. Aldinger, ed., DGM-Informationsgesellschaft Verlag, 1993, pp. 367-72.
P. Perrot: inTernary Alloys: A Comprehensive Compendium of Evaluated Constitutional Data and Phase Diagrams, G. Petzow and G. Effenberg, ed., VCH Verlagsgesellschaft, Weinheim, Germany, 1993, vol. 8, pp. 283–90.
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Wang, G.X., Dogan, B., Hsu, F.Y. et al. Microstructure and high-temperature tensile deformation of tiai(si) alloys made from elemental powders. Metall Mater Trans A 26, 691–701 (1995). https://doi.org/10.1007/BF02663918
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DOI: https://doi.org/10.1007/BF02663918