Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
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Shape Memory Characteristics and Mechanical Properties of Rapidly Solidified $Ti_{50}Ni_{20}Cu_{30}$ Alloy Strips

급냉응고된 $Ti_{50}Ni_{20}Cu_{30}$ 합금 스트립의 형상기억특성과 기계적특성

  • Kim, Yoen-Wook (Dept. of Advanced Materials Engineering, Keimyung University)
  • 김연욱 (계명대학교 공과대학 신소재공학과)
  • Published : 2009.10.31
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Abstract

Microstructures and shape memory characteristics of $Ti_{50}Ni_{20}Cu_{30}$ alloy strips fabricated by arc melt overflow have been investigated by means of XRD, optical microscopy and DSC. The microstructure of as-cast strips exhibited columnar grains normal to the strip surface. X-ray diffraction analysis showed that one-step martensitic transformation of B2-B19 occurred in the alloy strips. According to the DSC analysis, it was known that the martensitic transformation temperature ($M_s$) of B2 $\rightarrow$ B19 in $Ti_{50}Ni_{20}Cu_{30}$ strip is $57^{\circ}C$. During thermal cyclic deformation with the applied stress of 60 MPa, transformation hysteresis and elongation associated with the B2-B19 transformation were observed to be $3.7^{\circ}C$ and 1.6%, respectively. The as-cast strip of $Ti_{50}Ni_{20}Cu_{30}$ alloy also showed a superelasticity and its stress hysteresis was as small as 14 MPa. These mechanical properties and shape memory characteristics of the alloy strips were ascribed to B2-B19 transformation and the controlled microstructures produced by rapid solidification of the arc melt overflow process.

Keywords

References

  1. K. Otsuka and K, Shmizu: Scr. Metall., "Memory effect and thermoelastic martensite transformation in Cu-Al-Ni alloy", 4(6), 1970, 469-472 https://doi.org/10.1016/0036-9748(70)90087-6
  2. K. Otsuka and X. Ren: Progress in Materials Science, "Physical metallurgy of Ti-Ni-based shape memory alloy", 50, 2005, 511-678 https://doi.org/10.1016/j.pmatsci.2004.10.001
  3. T. H. Nam, T. Saburi and K. Shimizu: Master. Trans., JIM, "Shape memory characteristics associated with the B2$\leftrightarrow$B19 and B19$\leftrightarrow$B19' transformations in a Ti-40Ni-10Cu (at.%) alloy", 31(4), 1990, 262-269 https://doi.org/10.2320/matertrans1989.31.262
  4. H. Rsner, A.V. Shelyakov, A.M. Glezer, K. Feit and P. Schlo$\beta$macher, Mater. Sci. Eng., "A study of an amorphouscrystalline structured Ti-25Ni-25Cu (at.%) shape memory alloy", A273-A275, 1999, 733-737
  5. Y.W. Kim and T.H. Nam: Functional Materials, "Shape memory properties of rapidly solidified $Ti_{50}Ni_{50-\chi}Cu_{\chi}$($\chi$=20,25) alloy strips", 1(3), 2008, 203-208 https://doi.org/10.1142/S1793604708000368
  6. J.H. Kim, M.S Choi, H.W Lee, T.J. Kim, Y.W. Kim and T.H. Nam: J. Kor. Inst. Met. & Mater., "Phase transformation behavior and shape memory characteristics of Ti-Ni-Cu alloy ribbons fabricated by melt spinning", 40(7), 2002, 717-722
  7. Y. Kudoh, M. Tokomani, S. Miyazazaki and K. Otsuka: Acta Metall., "Crystal structure of the martensite in Ti-49.2 at.%Ni alloy analyzed by the single crystal X-ray diffraction method", 33, 1985, 2049-2056 https://doi.org/10.1016/0001-6160(85)90128-2
  8. M. Matsumoto, T. Tauzuki and Y. Furuya: proceedings of ICOMAT, "Thermoelastic phase transformation of melt-spun Ti50Ni50Cux (x=0-20at.%) ribbons", 1992, 971-9074
  9. T. H. Nam, T. Saburi and K. Shimizu: Master. Trans., JIM, "Shape memory characteristics associated with the B2$\leftrightarrow$B19 and B19$\leftrightarrow$B19′ transformations in a Ti-40Ni-10Cu (at.%) alloy", 31(4), 1990, 262-269
  10. S. Miyazaki. V.N. No, K. Kitamura, A. Khantachawana and H. Hosoda: Intnational J. Plas., "Texture of Ti-Ni rolled thin plates and sputter-deposited thin films", 16, 2000, 1135-1141 https://doi.org/10.1016/S0749-6419(00)00004-8