Document 
Eur. Phys. J. Special Topics 158, 21-26 (2008)
DOI: 10.1140/epjst/e2008-00648-4
Martensitic transformation in amorphous-crystalline Ti-Ni-Cu and Ti-Hf-Ni-Cu thin ribbons
N. Resnina1, S. Belyaev1 and A. Shelyakov21 Research Institute of Mathematics and Mechanics, Mathematics and Mechanics Faculty, Saint-Petersburg State University, Universitetsky pr. 28, 198504 Saint-Petersburg, Russia
2 Moscow Engineering Physics Institute, Kashirskaya 31, 115409 Moscow, Russia
natasha@smel.math.spbu.ru
(Published online: 1 May 2008)
Abstract
Martensitic transformations and strain variation in
amorphous-crystalline thin ribbons of Ti50Ni25Cu25,
Ti40.7Hf9.5Ni44.8Cu5 and
Ti40.7Hf9.5Ni39.8Cu10 alloys were investigated. The
amorphous-crystalline state in the samples was produced by an interruption
of the isothermal crystallization in DSC apparatus. The volume fraction of
the crystalline phase 
in the samples was varied from 10 to 100%. Transformation temperatures in amorphous-crystalline thin ribbons of
Ti50Ni25Cu25 alloy depended only slightly on the crystalline
volume fraction. On the contrary, the strong dependence of the martensitic
transformation temperatures on the volume of crystalline phase was obtained
in Ti40.7Hf9.5Ni44.8Cu5 and
Ti40.7Hf9.5Ni39.8Cu10 alloys. Moreover, it was found
that the intervals of the direct transformation are extremely narrow,
whereas the intervals of the reverse transformation are unusually wide. As
the crystalline volume fraction rises, both the direct transformation
interval and the reverse one decrease, and the transformation temperatures
increase. It was shown that increase of the Cu-content in
Ti40.7Hf9.5Ni
Cu
(x = 5, 10%) alloys results
in decrease of the transformation temperatures, of the temperature interval
of the reverse transformation on heating and of the hysteresis, while the
temperature interval of the direct transformation on cooling widens
© EDP Sciences, Springer-Verlag 2008