Abstract
The influence of cooling rates on the dendritic growth and microstructure evolution of Ti48Al2Cr2Nb alloy is studied by electromagnetic levitation combined with copper mold casting. The different cooling rates of the conical as-cast sample with diameters from 4.7 to 0.8 mm were calculated by ANSYS software. The results show that primary dendrite arm spacing decreases with increase in cooling rate. Peritectic transformation (L + β → α) and the transformation of α → (α2 + γ) are restrained at cooling rate of 2.3 × 104 K s−1. With further increase in cooling rate (2.6 × 104 K s−1), a fine and homogeneous microstructure can be observed in the conical casting sample with the diameter of 0.8 mm. It consists of a large amount of massive γ phase, lath-like γ phase, and only few lamellar structures (α2 + γ). The formation of the microstructure in the alloy is attributed to the strong chilling, giving rise to the high undercooling and the high dislocation density during rapid solidification.
Similar content being viewed by others
References
X.H. Wu, Review of Alloy and Process Development of TiAl Alloys, Intermetallics, 2006, 14, p 1114–1122
F. Appel, J.D.H. Paul, and M. Oehring, Gamma Titanium Aluminide Alloys, Science and Technology Wiley, Weinheim, 2011, p 1–20
Z.G. Liu, L.H. Chai, Y.Y. Chen, and F.T. Kong, Development of Rapidly Solidified Titanium Aluminide Compounds, Acta Metall., 2008, 44, p 569–573
L.C. Zhuo, S.J. Pang, H. Wang, and T. Zhang, Effect of Cooling Rate on Microstructure and Mechanical Properties of Rapidly Solidified Al-Based Bulk Alloys, J. Alloys Compd., 2010, 504S, p S117–S122
L.Y. Sheng, W. Zhang, J.T. Guo, L.Z. Zhou, and H.Q. Ye, Microstructure Evolution and Mechanical Properties’ Improvement of NiAl-Cr(Mo)-Hf Eutectic Alloy During Suction Casting and Subsequent HIP Treatment, Intermetallics, 2009, 17, p 1115–1119
C.D. Anderson, W.H. Hofmeisiter, and R.J. Bayuzick, Solidification Kinetics and Metastable Phase Formation in Binary Ti-Al, Metall. Trans. A, 1992, 23A, p 2699–2714
O. Shuleshova, T.G. Woodcock, H.G. Lindenkreuz, R. Hermann, W. Löser, and B. Büchner, Metastable Phase Formation in Ti-Al-Nb Undercooled Melts, Acta Mater., 2007, 55, p 681–689
W. Löser, H.G. Lindenkreuz, R. Hermann, O. Shuleshova, and T.G. Woodcock, Recalescence Behaviour of Binary Ti-Al and Ternary Ti-Al-Nb Undercooled Melts, Mater. Sci. Eng. A, 2005, 413, p 398–402
Y.H. Zhou, Z.Q. Hu, and W.Q. Jie, Solidification Technology, China Machine Press, Beijing, 1998, p 227–244
Z.G. Liu, L.H. Chai, Y.Y. Chen, F.T. Kong, H.A. Davies, and I.A. Figueroa, Microstructure Evolution in Rapidly Solidified Y Added TiAl Ribbons, Intermetallics, 2011, 19, p 160–164
Z.G. Liu, Effect of Cooling Rate and Y Element on the Microstructure of Rapidly Solidified TiAl Alloys, J. Alloys Compd., 2010, 504S, p S491–S495
Z.G. Liu, Y.Y. Chen, L.H. Chai, F.T. Kong, and H.A. Davies, Production and Characterization of TiAl Ribbons with Y Additions, Trans. Nonferrous Met. Soc. China, 2006, 16, p s711–s714
H.W. Wang, D.D. Zhu, C.M. Zou, and Z.J. Wei, Microstructure and Nanohardness of Ti-48%Al Alloy Prepared by Rapid Solidification Under Different Cooling Rates, Trans. Nonferrous Met. Soc. China, 2011, 21, p s328–s332
L.H. Chai, Microstructral Evolution of Rapidly Solidified TiAl Based Alloys, PhD thesis, Harbin Institute of Technology, Harbin, 2010
X.F. Ding, J.P. Lin, H. Qi, L.Q. Zhang, X.P. Song, and G.L. Chen, Microstructure Evolution of Directionally Solidified Ti-45Al-8.5Nb-(W, B, Y) Alloys, J. Alloys Compd., 2011, 509, p 4041–4046
J.L. Fan, X.Z. Li, Y.Q. Su, R.R. Chen, J.J. Guo, and H.Z. Fu, Microstructure Evolution of Directionally Solidified Ti-46Al-0.5W-0.5Si alloy, J. Cryst. Growth, 2011, 337, p 52–59
J. Lapin and Z. Gabalcová, Solidification Behaviour of TiAl-Based Alloys Studied by Directional Solidification Technique, Intermetallics, 2011, 19, p 797–804
J.L. Fan, X.Z. Li, Y.Q. Su, J.J. Guo, and H.Z. Fu, Effect of Growth Rate on Microstructure Parameters and Microhardness in Directionally Solidified Ti-49Al Alloy, Mater. Des., 2012, 34, p 552–558
D.M. Stefanescu, Science and Engineering of Casting Solidification, 2nd ed., Springer, Columbus, 2009, p 177–181
J.S. Kirkaldy and D. Venugopalan, Pattern Selection Relations for Deep-Rooted Binary Alloy Cells, Scr. Mater., 1989, 23, p 1603–1608
D. Bouchard and J.S. Kirkaldy, Prediction of Dendrite Arm Spacings in Unsteady-and Steady-State Heat Flow of Unidirectionally Solidified Binary Alloys, Metall. Mater. Trans. B, 1997, 28B, p 651–663
M. Paliwal and I.H. Jung, The Evolution of the Growth Morphology in Mg–Al Alloys Depending on the Cooling Rate During Solidification, Acta Mater., 2013, 61, p 4848–4860
U. Böyük and N. Maraşlı, The Microstructure Parameters and Microhardness of Directionally Solidified Sn-Ag-Cu Eutectic Alloy, J. Alloys Compd., 2009, 485, p 264–269
G.L. Chen, X.J. Xu, Z.K. Teng, Y.L. Wang, and J.P. Lin, Microsegregation in High Nb Containing TiAl Alloy Ingots Beyond Laboratory Scale, Intermetallics, 2007, 15, p 625–631
Y.Q. Liu, W.T. Xu, D. Xie, and Z.M. Li, Phase Diagram Calculations of Al-Cr-Nb-Ti Quaternary System, Mater. Res. Innovations, 2014, 18, p 573–578
Z. Xiao, L. Zheng, J. Yan, L. Yang, and H. Zhang, Lamellar Orientations and Growth Directions of β Dendrites in Directionally Solidified Ti-47Al-2Cr-2Nb Alloy, J. Cryst. Growth, 2011, 324, p 309–313
R.M. Imayev, V.M. Imayev, M. Oehring, and F. Appel, Alloy Design Concepts for Refined Gamma Titanium Aluminide Based Alloys, Intermetallics, 2007, 15, p 451–460
P.X. Fu, X.H. Kang, Y.C. Ma, K. Liu, D.Z. Li, and Y.Y. Li, Centrifugal Casting of TiAl Exhaust Valves, Mater. Sci. Eng. A, 1997, 239–240, p 570–576
K.B. Bisen, M. Arenas, N. El-Kaddah, and V.L. Acoff, Computation and Validation of Weld Pool Dimensions and Temperature Profiles for Gamma TiAl, Metall. Mater. Trans. A, 2003, 34A, p 2273–2279
O. Shuleshova, D. Holland-Moritz, W. Löser, A. Voss, H. Hartmann, U. Hecht, V.T. Witusiewicz, D.M. Herlach, and B. Büchner, In Situ Observations of Solidification Processes in γ-TiAl Alloys by Synchrotron Radiation, Acta Mater., 2010, 58, p 2408–2418
D.D. Zhu, H.W. Wang, J.Q. Qi, C.M. Zou, and Z.J. Wei, Effect of Cr Addition on Microstructures and Nanohardness of Rapidly Solidified Ti-48Al Alloy, Mater. Sci. Technol., 2012, 28, p 1385–1390
D. Daloz, U. Hecht, J. Zollinger, H. Combeau, A. Hazotte, and M. Založnik, Microsegregation, Macrosegregation and Related Phase Transformations in TiAl Alloys, Intermetallics, 2011, 19, p 749–756
S.R. Dey, A. Hazotte, and E. Bouzy, Crystallography and Phase Transformation Mechanisms in TiAl-Based Alloys—A Synthesis, Intermetallics, 2009, 17, p 1052–1064
X.Z. Li, J.L. Fan, Y.Q. Su, D.M. Liu, J.J. Guo, and H.Z. Fu, Lamellar Orientation and Growth Direction of α Phase in Directionally Solidified Ti-46Al-0.5W-0.5Si Alloy, Intermetallics, 2012, 27, p 38–45
L. Xie, Y. Liu, Y.T. Wang, J. Zheng, and X.G. Li, Superior Hydrogen Storage Kinetics of MgH2 Nanoparticles Doped with TiF3, Acta Mater., 2007, 55, p 4585–4591
J.S. Pan, J.M. Tong, and M.B. Tian, Material Science Foundation, Peking University Press, Beijing, 2011, p 550–659
S.A. Maloy and G.T. Gray, High Strain Rate Deformation of Ti-48Al-2Nb-2Cr, Acta Mater., 1996, 44, p 1741–1756
S.Y. Zhou, R. Hu, J.S. Li, H. Chang, H.C. Kou, and L. Zhou, Stress Induced Deformation in the Solidification of Undercooled Co80Pd20 Alloys, Mater. Sci. Eng. A, 2011, 3, p 973–977
X.L. Xu, Y.Z. Chen, and F. Liu, Study of Microstrain in Rapidly Solidified Structures of Hypercooled Co80Pd20 Alloys, Mater. Sci. Technol., 2013, 29, p 117–120
Acknowledgment
The author would like to acknowledge the financial support from the National Basic Research Program of China (No. 2011CB605503).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liu, Y., Hu, R., Zhang, T. et al. Dendritic Growth and Microstructure Evolution with Different Cooling Rates in Ti48Al2Cr2Nb Alloy. J. of Materi Eng and Perform 25, 38–45 (2016). https://doi.org/10.1007/s11665-015-1696-6
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11665-015-1696-6