Determination of Phase Transformation and Activation Energy in High Temperature Shape Memory TiVAl Alloy

Abstract

T i-V-Al alloys are a good candidates for lightweight high temperature shape memory alloys. Due to their excellent mechanical properties with low density, in industrial applications, there are widely used as high temperature shape memory alloys. However, Ti-V-Al alloys have cold workability. Because of this feature, machinability in different forms is quite easy and cheap. In this work, microstructure and phase transformation of Ti-V-Al alloy produced by arc-melting method were investigated. The phase formations, microstructures, martensite-austenite transformation temperatures were characterized using XRD, SEM and DSC. Activation energies of the alloy were calculated by Kissinger and Osawa methods

Keywords

• High Temperature, Shape memory alloys, Phase transformations, Martensitic transformation, Activation energy

References

1. Kissinger, H. E. Reaction Kinetics in Differential Thermal Analysis. Analytical Chemistry. 29 No. 11, National Bureau of Standards, Washington, pp. 1702-1706, 1957.
2. Ozawa, T. A new method of analyzing thermogravimetric data. Chem. Soc. Jpn 38 (11) (1965) 1881-1886.
3. Cui, Y., Li Y., Luo K., Xu H. Microstructure and shape memory effect of Ti–20Zr–10Nb alloy. Mat. Sci. Eng. A. 527 (2010) 652-656.
4. Ma, L.W., Cheng, H.S., Chung, C.Y., Yuan, B. Effect of heat treatment time on microstructure and mechanical properties of Ti–19Nb–9Zr (at%) shape memory alloy. Materials Science & Engineering A 561 (2013) 427–433.
5. Zheng XH, Sui JH, Zhang X, Tian XH, Cai W. Effect of Y addition on the martensitic transformation and shape memory effect of Ti-Ta high-temperature shape memory alloy.Journal of Alloys and Compounds 539 (2012) 144- 147.
6. Takahashi, E., Sakurai, T., Watanabe, S., Masahashi, N., Hanada, S. Effect of heat treatment and Sn content on superelasticity in biocompatible TiNbSn alloy. Mater. Trans. 43 (12) (2002) 2978–2983.
7. Acar E. Dynamic mechanical response of a Ni45.7Ti29.3Hf20Pd5 alloy. Materials Science and Engineering :A (2015) 633 169-175.
8. Fang, H., Wong, B., Bai, Y. Kinetic modeling of thermophysical properties of shape memory alloys during phase transformation. Construction and Building Materials 131 (2017) 146-155.