Journal of Materials Science

, Volume 14, Issue 6, pp 1339–1343 | Cite as

Thermal conversion efficiency of an ideal thermoelastic marmem cycle

  • H. A. Mohamed
Papers

Abstract

The thermal conversion efficiency of an ideal stress-strain-temperature cycle based on the mechanical shape memory effect associated with a thermoelastic martensite transformation (thermoelastic marmem cycle) has been studied. A relationship between the upper limit of the thermal efficiency and a set of materials properties has been derived. It is shown that a higher thermoelastic marmem efficiency and a closer approach to the corresponding Carnot efficiency are favoured by: (1) higher yield stress of the high-temperature phase, (2) larger recoverable strain, (3) smaller transformation temperature range and thermal hysteresis associated with the transformation, and (4) smaller transformation latent heat. The thermal efficiency has been calculated for a cycle utilizing a Ti-50.4 at % Ni alloy. The highest efficiency for this particular alloy was found to be about 9%; this amounts to 45% of the corresponding Carnot efficiency. Thus it is concluded that efficiencies can be obtained which are comparable with those of cycles operating at small temperature differences with fluids as working media.

Keywords

Martensite Thermal Efficiency Shape Memory Memory Effect Shape Memory Effect 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. Perkins, editor, “Shape Memory Effects in Alloys” (Plenum Press, New York, 1975).Google Scholar
  2. 2.
    H. A. Mohamed and J. Washburn, J. Mater. Sci. 12 (1977) 469.Google Scholar
  3. 3.
    C. M. Wayman, in “Shape Memory Effects in Alloys” (Plenum Press, New York, 1975) p. 1.Google Scholar
  4. 4.
    L. Delaey, R. V. Krishnan, H. Tas and H. Warlimont, J. Mater. Sci. 9 (1974) 1521.Google Scholar
  5. 5.
    B. Cunningham and K. H. G. Ashbee, Acta Met. 25 (1977) 1315.Google Scholar
  6. 6.
    R. Banks and M. Wahlig, Presented at the International Solar Energy Society Meeting, Winnepeg, Canada, August 1976; Lawrence Berkeley Laboratory Report LBL-5293.Google Scholar
  7. 7.
    R. Banks, in “Shape Memory Effects in Alloys” (Plenum Press, New York, 1975) p. 537.Google Scholar
  8. 8.
    A. A. Golestaneh, J. Appl. Phys. 49 (1978) 1241.Google Scholar
  9. 9.
    H. C. Tong and C. M. Wayman, Met. Trans. 6A (1975) 29.Google Scholar
  10. 10.
    M. Ahlers, Scripta Met. 8 (1975) 71.Google Scholar
  11. 11.
    H. C. Tong and C. M. Wayman, ibid 8 (1974) 93.Google Scholar
  12. 12.
    H. A., Mohamed, J. Mater. Sci. 13 (1978) 2728.Google Scholar
  13. 13.
    Idem, ibid 13 (1978) 1364.Google Scholar
  14. 14.
    W. B. Cross, A. H. Karigits and F. J. Stimler, “Nitinol Characterization Study”, NASA Contractor Report (1969) Cr-1433.Google Scholar
  15. 15.
    C. M. Jackson, H. J. Wagner and R. J. Wasilewski, “55-Nitinol — The Alloy with a Memory: Its Physical Metallurgy, Properties, and Applications”, NASA Report (1972) SP 5110.Google Scholar
  16. 16.
    D. S. Lieberman, M. S. Wechsler and T. A. Read, J. Appl. Phys. 26 (1955) 473.Google Scholar
  17. 17.
    H. A. Mohamed, Ph. D. Thesis, University of California, Berkeley (1976), Lawrence Berkeley Laboratory Report LBL-5112.Google Scholar
  18. 18.
    S. P. Gupta and A. A. Johnson, Trans. Jap. Inst. Metals 14 (1973) 292.Google Scholar
  19. 19.
    D. Prigmore and R. Barber, Solar Energy 17 (1975) 185.Google Scholar
  20. 20.
    H. Tabor and L. Bronicki, “Small Turbine for Solar Power Package” in Proceedings of the United Nations Conference on New Sources of Energy”, Vol. 4 (Solar Energy: 1) (United Nations Publications, 1964) p. 68.Google Scholar
  21. 21.
    C. M. Wayman and K. Shimizu, Met. Sci. J. 6 (1972) 175.Google Scholar
  22. 22.
    I. E. Wang, W. T. Buehlerand and P. J. Pickert, J. Appl. Phys. 36 (1965) 3232.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1979

Authors and Affiliations

  • H. A. Mohamed
    • 1
  1. 1.Energy and Environment Division, Lawrence Berkeley LaboratoryUniversity of CaliforniaBerkeleyUSA

Personalised recommendations