Abstract
The microstructure and orientation relationship (OR) of the α2 and ωo phases in the Ti–34Al–13Nb (at. %) alloy were investigated. The α2 segments nucleated at the ωo boundaries after aging at 900 °C for 2 h. The ORs between the two phases were studied by selected area diffraction patterns using a transmission electron microscope and interpreted by the superimposed stereographic projections. Two ORs were defined as follows: \( \left[ {1\bar{2}10} \right]\upalpha_{2} //\left[ {000\bar{1}} \right]\upomega_{o} \); \( (0002)\upalpha_{2} //\left[ {\bar{1}2\bar{1}0} \right]\upomega_{o} \) and \( \left[ {\bar{1}010} \right]\upalpha_{2} //\left[ {2\bar{4}2\bar{3}} \right]\upomega_{o} \); \( \left( {0002} \right)\upalpha_{2} //\left( {01\overline{12} } \right)\upomega_{o} \). Two α2 laths with parallel \( \left\langle {\bar{1}102} \right\rangle \) directions were observed in this alloy, which were explained by the different α2 variants nucleated at the ωo boundaries according to ORI and ORII.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Kim YW (1995) Gamma titanium aluminides. JOM 47:38
Paul JDH, Appel F, Wagner R (1998) The compression behaviour of niobium alloyed γ-titanium alumindies. Acta Mater 46:1075–1085
Appel F, Wagner R (1998) Microstructure and deformation of two-phase γ-titanium aluminides. Mater Sci Eng R Rep 22:187–268
Kim YW, Rosenberger A, Dimiduk DM (2009) A Study on the composite blade performance variation by attaching erosion shield for hovercraft. Intermetallics 17:1017–1027
Chen GL, Xu XJ, Teng ZK, Wang YL, Lin JP (2007) Microsegregation in high Nb containing TiAl alloy ingots beyond laboratory scale. Intermetallics 15:625–631
Witusiewicz VT, Bondar AA, Hecht U, Velikanova TY (2009) The Al–B–Nb–Ti system: IV. Experimental study and thermodynamic re-evaluation of the binary Al–Nb and ternary Al–Nb–Ti systems. J Alloy Compd 472:133–161
Bendersky LA, Boettinger WJ, Burton BP, Biancaniello FS, Shoemaker CB (1990) The formation of ordered ω-related phases in alloys of composition Ti4Al3Nb. Acta Metall Mater 38:931–943
Song L, Zhang LQ, Xu XJ, Sun J, Lin JP (2013) Omega phase in as-cast high-Nb-containing TiAl alloy. Scr Mater 68:929–932
Stark A, Bartels A, Clemens H, Schimansky FP (2008) On the formation of ordered ω-phase in high Nb containing γ-TiAl based alloys. Adv Eng Mater 10:929–934
Song L, Xu XJ, You L, Liang YF, Lin JP (2014) Phase transformation and decomposition mechanisms of the βo(ω) phase in cast high Nb containing TiAl alloy. J Alloy Compd 616:483–491
Song L, Xu X, You L, Liang Y, Wang Y, Lin J (2015) Ordered α2 to ωo phase transformations in high Nb-containing TiAl alloys. Acta Mater 91:330–339
Huang ZW, Cong T (2010) Microstructural instability and embrittlement behaviour of an Al-lean, high-Nb γ-TiAl-based alloy subjected to a long-term thermal exposure in air. Intermetallics 18:161–172
Langmayr F, Fratzl P, Vogl G, Miekeley W (1994) Crossover from ω-phase to α-phase precipitation in bcc Ti-Mo. Phys Rev B 49:11759–11766
Yamamoto A, Tsubakino H (1998) Convergent beam dark field imaging technique with its application to observation of multiphase materials. Mater Trans JIM 39:989–994
Nag S, Banerjee R, Stechschulte J, Fraser HL (2005) Comparison of microstructural evolution in Ti-Mo-Zr-Fe and Ti-15Mo biocompatible alloys. J Mater Sci Mater Med 16:679–685
Ohmori Y, Ogo T, Nakai K, Kobayashi S (2001) Effects of ω-phase precipitation on β → α, α transformations in a metastable β titanium alloy. Mater Sci Eng A 312:182–188
Prima F, Vermaut P, Texier G, Ansel D, Gloriant T (2006) Evidence of α-nanophase heterogeneous nucleation from ω particles in a β-metastable Ti-based alloy by high-resolution electron microscopy. Scr Mater 54:645–648
Nag S, Banerjee R, Srinivasan R, Hwang JY, Harper M, Fraser HL (2009) ω-Assisted nucleation and growth of α precipitates in the Ti–5Al–5Mo–5V–3Cr–0.5 Fe β titanium alloy. Acta Mater 57:2136–2147
Usikov MP, Zilbershtein VA (1973) The orientation relationship between the α- and ω-phases of titanium and zirconium. Phys Status Solidi A 19:53–58
Vohra YK, Sikka SK, Menon ESK, Krishnan R (1980) Direct evidence of intermediate state during alpha-omega transformation in Ti–V alloy. Acta Metall 28:683–685
Gupta SC, Sikka SK, Chidambaram R (1985) On orientation relations between α and ω phases in Zr by texture studies using neutron diffraction method. Scripta Metall 19:1167–1169
Zhang MX, Kelly PM (2005) Edge-to-edge matching model for predicting orientation relationships and habit planes—the improvements. Scripta Mater 52:963–968
Huang ZW (2013) Thermal stability of Ti–44Al–4Nb–4Zr–0.2Si–1B alloy. Intermetallics 42:170–179
Howe JM, Prabhu N (1990) The structure of kinks at dislocation interphase boundaries and their role in boundary migration—I. Experimental observation of kink motion. Acta Metall Mater 38:881–887
Wang SC, Aindow M, Starink MJ (2003) Effect of self-accommodation on α/α boundary populations in pure titanium. Acta Mater 51:2485–2503
Kelly PM, Zhang MX (2006) Edge-to-edge matching—the fundamentals. Metall Mater Trans A 37:833–839
Srivastava D, Madangopal K, Banerjee S, Ranganathan S (1993) Self accomodation morphology of martensite variants in Zr-2.5 wt%Nb alloy. Acta Metall Mater 41:3445–3454
Madangopal K, Singh JB, Banerjee S (1993) The nature of self-accommodation in Ni-Ti shape memory alloys. Scripta Metall Mater 29:725–728
Acknowledgements
This research was supported by the National Natural Science Foundation of China (No. 51271016), and the National Basic Research Program of China (973 Program, No. 2011CB605500).
Author information
Authors and Affiliations
Corresponding authors
Rights and permissions
About this article
Cite this article
Ye, T., Song, L., Quan, M.H. et al. Phase transformations in Ti–34Al–13Nb alloy. J Mater Sci 51, 10478–10486 (2016). https://doi.org/10.1007/s10853-016-0267-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-016-0267-z