Microstructure and Phase Transformation Behavior of a Stress-Assisted Heat-Treated Ti-Rich NiTi Shape Memory Alloy

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• 作者：A. Ahadi (1)
  E. Rezaei (1) Ebad.rezaie@gmail.com
• 关键词：mechanical twins – stress accommodation – stress ; assisted heat treatment – two ; stage phase transformation
• 刊名：Journal of Materials Engineering and Performance
• 出版年：2012
• 出版时间：August 2012
• 年：2012
• 卷：21
• 期：8
• 页码：1806-1812
• 全文大小：810.6 KB
• 参考文献：1. T. Duerig, A. Pelton, and D. St?ckel, An Overview of Nitinol Medical Applications, Mater. Sci. Eng. A., 1999, 273–275, p 149–160
  2. D.C. Lagoudas, Shape Memory Alloys Modeling and Engineering Applications, first ed., 2008, Springer, New York, p 30
  3. T. Kurita, H. Matsumoto, and H. Abe, Transformation Behavior in Rolled NiTi, J. Alloys Compd., 2004, 381, p 158–161
  4. J.I. Kim, Y. Liu, and S. Miyazaki, Ageing-Induced Two-Stage R-Phase Transformation in Ti-50.9at.%Ni, Acta Mater., 2004, 52, p 487–499
  5. Y. Zheng, F. Jiang, L. Li, H. Yang, and Y. Liu, Effect of Ageing Treatment on the Transformation Behavior of Ti-50.9 at.% Ni Alloy, Acta Mater., 2008, 56, p 736–745
  6. H.F. Lopez, A. Salinas-Rodriguez, and J.L. Rodriguez-Galicia, Microstructural Aspects of Precipitation and Martensitic Transformation in a Ti-Rich Ni-Ti Alloy, Scr. Mater., 1996, 34, p 659–664
  7. K. Otsuka and X. Ren, Physical Metallurgy of Ti-Ni-Based Shape Memory Alloys, Prog. Mater. Sci., 2005, 50, p 511–678
  8. A.S. Paula, K.K. Mahesh, C.M.L. dos Santos, F.M. Braz Fernandes, and C.S. da Costa Viana, Thermomechanical Behavior of Ti-Rich NiTi Shape Memory Alloys, Mater. Sci. Eng. A, 2008, 481–482, p 146–150
  9. M.H. Wu, Fabrication of Nitinol Materials and Components, Mater. Sci. Forum, 2002, 394–395, p 285–292
  10. K.S. Kim, K.K. Jee, W.C. Kim, W.Y. Jang, and S.H. Han, Effect of Heat Treatment Temperature on Oxidation Behavior in Ni-Ti Alloy, Mater. Sci. Eng. A, 2008, 481–482, p 658–661
  11. B. Bertheville and J.-E. Bidaux, Alternative Powder Metallurgical Processing of Ti-Rich NiTi Shape-Memory Alloys, Scr. Mater., 2005, 52, p 507–512
  12. Y. Liu, Z. Xie, J. Van Humbeeck, L. Delaey, and Y. Liu, On the Deformation of the Twinned Domain in NiTi Shape Memory Alloys, Philos. Mag. A, 2000, 80, p 1935–1953
  13. M. Nishida, H. Ohgi, I. Itai, A. Chiba, and K. Yamauchi, Electron Microscopy Studies of Twin Morphologies in B19′ Martensite in the Ti-Ni Shape Memory Alloy, Acta. Metal. Mater., 1995, 43, p 1219–1227
  14. W.J. Moberly, T.W. Duerig, J.L. Proft, and R. Sinclair, Mechanical Twinning and Plasticity in Ti-Ni-Fe (3%), Mater. Sci. Forum, 1990, 56–58, p 759–764
  15. E. Hornbogen, Ausforming of NiTi, J. Mater. Sci., 1999, 34, p 599–606
  16. A.V. Kulkarni, Effect of Ausforming via Severe Plastic Deformation on Shape Memory Behavior of NiTi, M.Sc. Thesis, 2004, Texas A&M University, p 42.
  17. W.J. Moberly, Mechanical Twining and Twinless Martensite in Ternary TixNi(50?x)Mx, PhD Thesis, Stanford University, 1991, p 214.
  18. W.J. Moberly, Mechanical Twining and Twinless Martensite in Ternary TixNi(50?x)Mx, PhD Thesis, Stanford University, 1991, p 204.
  19. A. Ahadi, A. Karimi Taheri, K. Karimi Taheri, I.S. Sarraf, S.M. Abbasi, The Effect of Deformation Heating on Restoration and Constitutive Equation of a Wrought Equi-Atomic NiTi Alloy, J. Mater. Eng. Perform., 2011. doi:10.1007/s11665-011-9936-x.
  20. J. Uchil, K. Ganesh Kumara, and K.K. Mahesh, Effect of Thermal Cycling on R-Phase Stability in a NiTi Shape Memory Alloy, Mater. Sci. Eng. A, 2002, 332, p 25–28
  21. Y. Liu, M. Blanc, G. Tan, J.I. Kim, and S. Miyazaki, Effect of Ageing on the Transformation Behaviour of Ti-49.5 at.% Ni, Mater. Sci. Eng. A, 2006, 438–440, p 617–621
  22. A.S. Paula, J.P.H.G. Canejo, R.M.S. Martins, and F.M. Braz Fernandes, Effect of Thermal Cycling on the Transformation Temperature Ranges of a Ni-Ti Shape Memory Alloy, Mater. Sci. Eng. A, 2004, 378, p 92–96
  23. G. Fan, Y. Zhou, W. Chen, S. Yang, X. Ren, and K. Otsuka, Precipitation Kinetics of Ti3Ni4 in Polycrystalline Ni-Rich TiNi Alloys and Its Relation to Abnormal Multi-Stage Transformation Behavior, Mater. Sci. Eng. A, 2006, 438–440, p 622–626
  24. S.H. Chang, S.K. Wu, and G.H. Chang, Grain Size Effect on Multiple-Stage Transformations of a Cold-Rolled and Annealed Equiatomic TiNi Alloy, Scr. Mater., 2005, 52, p 1341–1346
  25. H.F. Lopez, A. Salinas, and H. Calderon, Plastic Straining Effects on the Microstructure of a Ti-Rich NiTi Shape Memory Alloy, Met. Metall. Mater. Trans. A, 2001, 32A, p 717–729
  26. E. Bataillard, J.-E. Bidaux, and R. Gotthardt, Interaction Between Microstructure and Multiple-Step Transformation in Binary NiTi Alloys Using In-Situ Transmission Electron Microscopy Observations, Phil. Mag., 1998, 78, p 327–344
  27. X.T. Zu, L.B. Lin, Z.G. Wang, S. Zhu, L.P. You, L.M. Wang, and Y. Huo, Influence of Electron Irradiation on the Martensitic Transformation of a Binary TiNi Shape Memory Alloy, J. Alloys Compd., 2003, 351, p 87–90
• 作者单位：1. Department of Materials Science and Engineering, Sharif University of Technology, Azadi Avenue, Tehran, Iran
• ISSN：1544-1024

文摘

In this study, the effects of stress-assisted heat treatment on the microstructure and phase transformation of a Ti-rich (Ti-49.52 at.% Ni) shape memory alloy were investigated. For this purpose, the alloy was heat treated at temperature of 500 °C for 10 h under applied stresses of 100 and 200 MPa. XRD, TEM, and repeated thermal cycling were employed to study the microstructure and transformation behavior of the heat-treated materials. Room temperature XRD diffractogram of the stress-free heat-treated material showed a weak reflection of austenite (B2), while that for the stress-assisted heat-treated materials had a high intensity implying the presence of residual austenite in the microstructure. TEM observations confirmed the presence of residual austenite and revealed mechanical twins as another constituent of the microstructure in the stress-assisted heat-treated materials. Moreover, with increasing the value of applied stress the size of mechanical twins was increased and a high density of structural defects was observed at the interfaces of the twins. DSC results demonstrated two-stage transformation in the initial cycles of transformation in the stress-assisted heat-treated material. After about eight cycles of transformation, the two-stage transformation has vanished, and a single-stage transformation remained up to 100 cycles. It was suggested that the accommodation of stresses at Ti₂Ni/matrix interface provides a suitable condition for local transformation of B2 to B19′ that is manifested by a two-stage phase transformation. Introduction of structural defects during repeated thermal cycling may counteract the stress field at Ti₂Ni/matrix interface leading to a single-stage transformation.