Numéro
J. Phys. Colloques
Volume 43, Numéro C4, Décembre 1982
ICOMAT-82
International Conference on Martensitic Transformations
Page(s) C4-541 - C4-546
DOI https://doi.org/10.1051/jphyscol:1982484
ICOMAT-82
International Conference on Martensitic Transformations

J. Phys. Colloques 43 (1982) C4-541-C4-546

DOI: 10.1051/jphyscol:1982484

EFFECT OF AUSAGING ON THE MORPHOLOGY OF MARTENSITE IN Fe-Ni-Ti-Co ALLOYS

T. Maki1, K. Kobayashi2 et I. Tamura1

1  Department of Metal Science and Technology, Faculty of Engineering, Kyoto University, Sakyo-ku, Kyoto 606, Japan
2  Graduate School of Kyoto University, Sakyo-ku, Kyoto 606, Japan


Abstract
The change in martensite morphology with ausaging in Fe-31%Ni-3%Ti and Fe-31%Ni-3%Ti-10%Co alloys has been examined. By the ausaging, austenite hardness and Ms temperature changed with the precipitation of coherent ordered fcc γ'-Ni3Ti. It was found that in the case of Fe-Ni-Ti-Co alloy the thin plate martensite formed in both solution treated and ausaged specimens, and the formation temperature of thin plate martensite was markedly increased by ausaging, whereas only the lenticular martensite was formed in Fe-Ni-Ti alloy. Present results indicated that the addition of Co to Fe-Ni-Ti alloy and the ausaging were favorable for the formation of thin plate martensite. Thin plate martensite in Fe-Ni-Ti-Co alloy showed a good (but not complete) shape memory effect in both solution treated and ausaged specimens, although the martensite was not typically thermoelastic.