Advertisement

Reversible Negative Thermal Expansion Response and Phase Transformation Behavior of a Ti-Rich Ti54Ni46 Alloy Prepared by Rapid Solidification

  • Zhong-Xun Zhao
  • Xiao Ma
  • Cai-You Zeng
  • Shanshan Cao
  • Chang-Bo Ke
  • Xin-Ping Zhang
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

In this study, a Ti-rich Ti–Ni alloy (Ti54Ni46) was prepared by rapid solidification technique through vacuum suction casting into a water-cooled copper mold. The microstructure, thermal expansion, and phase transformation behavior of the alloy were studied systematically. The results show that the rapidly solidified Ti54Ni46 alloy exhibits negative thermal expansion (NTE) response in both vertical and horizontal measuring directions upon heating and cooling. The discrepancy in the NTE response between the two mutually perpendicular directions of the alloy is small, indicating an implicit anisotropic NTE behavior. A one-to-one correspondence exists between the characteristic temperatures of phase transformation and NTE, as well as between their changes during thermal cycling. It is conclusive that the NTE strains generated upon heating and cooling originate from the volume changes accompanying the forward and reverse martensitic transformations in Ti54Ni46 alloy. Characteristic temperatures of both phase transformation and NTE of the alloy rapidly shift to lower temperatures due to the multiplication of dislocations during the initial approximately 20 thermal cycles, and then tend to be relatively unchanged in subsequent thermal cycling as the transformation-induced defects reach saturation. The absolute values of the coefficient of thermal expansion of the NTE stage upon heating and cooling decrease rapidly during the initial approximately 20 thermal cycles, and thereafter become relatively stable with the increase of thermal cycle number, which is mainly attributed to the decrease of the effective fraction of the B19′ martensite participating in the forward and reverse martensitic transformations.

Keywords

Rapid solidification Ti-rich Ti–Ni alloy Thermal cycling Negative thermal expansion Phase transformation 

Notes

Acknowledgements

This work was supported by the National Natural Science Foundation of China under Grant Nos. 51571092 and 51401081, and Key Project Program of Guangdong Provincial Natural Science Foundation under Grant No. S2013020012805.

References

  1. 1.
    Shiga M (1996) Invar alloys. Curr Opin Solid State Mater Sci 1(3):340–348CrossRefGoogle Scholar
  2. 2.
    Kim HY, Wei L, Kobayashi S, Tahara M, Miyazaki S (2013) Nanodomain structure and its effect on abnormal thermal expansion behavior of a Ti–23Nb–2Zr–0.7Ta–1.2O alloy. Acta Mater 61(13):4874–4886CrossRefGoogle Scholar
  3. 3.
    Monroe JA, Gehring D, Karaman I, Arroyave R, Brown DW, Clausen B (2016) Tailored thermal expansion alloys. Acta Mater 102:333–341CrossRefGoogle Scholar
  4. 4.
    Zhao ZX, Ma X, Cao SS, Ke CB, Zhang XP (2017) Anisotropic negative thermal expansion behavior of the as-fabricated Ti-rich and equiatomic Ti–Ni alloys induced by preferential grain orientation. Shape Mem Superelasticity.  https://doi.org/10.1007/s40830-017-0145-9 (in press)
  5. 5.
    Li YY, Yao XY, Cao SS, Ma X, Ke CB, Zhang XP (2017) Rapidly solidified and optimally constraint-aged Ni51Ti49 shape memory alloy aiming at making a purpose-designed bio-actuator. Mater Design 118:99–106CrossRefGoogle Scholar
  6. 6.
    Li YY, Cao SS, Ma X, Ke CB, Zhang XP (2017) Influence of strongly textured microstructure on the all-round shape memory effect of rapidly solidified Ni51Ti49 alloy. Mater Sci Eng, A 705:273–281CrossRefGoogle Scholar
  7. 7.
    McCormick PG, Liu Y (1994) Thermodynamic analysis of the martensitic transformation in NiTi—II. Effect of transformation cycling. Acta Metall Mater 42(7):2407–2413CrossRefGoogle Scholar
  8. 8.
    Soejima Y, Motomura S, Mitsuhara M, Inamura T, Nishida M (2016) In situ scanning electron microscopy study of the thermoelastic martensitic transformation in Ti–Ni shape memory alloy. Acta Mater 103:352–360CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  • Zhong-Xun Zhao
    • 1
  • Xiao Ma
    • 1
  • Cai-You Zeng
    • 1
  • Shanshan Cao
    • 1
  • Chang-Bo Ke
    • 1
  • Xin-Ping Zhang
    • 1
  1. 1.School of Materials Science and EngineeringSouth China University of TechnologyGuangzhouChina

Personalised recommendations