J. Phys. IV France
Volume 112, October 2003
Page(s) 713 - 716

J. Phys. IV France
112 (2003) 713
DOI: 10.1051/jp4:2003982

A study of transformations in titanium nickelide by simultaneous measurements of strain, electrical resistance and thermal effects

S.A. Egorov, M.E. Evard and N.N. Resnina

Saint-Petersburg State University, Research Institute of Mathematics and Mechanics, Laboratory for Strength of Materials, Universitetsky Pr. 28, Stary Petergof, Saint-Petersburg 198504, Russia

The results of simultaneous measurements of electrical resistance, stress and strain of Ti-Ni alloys at thermocycling and during the isothermal deformation are presented. It is shown that noticeable part of strain recovery in heating takes place before the start of the reverse transformation and is connected with twinning. The isothermalloading initiates the $B2{\to}B19'$ and $R{\to}B19'$ transformations and produce almost no effect on the $B2{\to}R$ transformation. The results of differential thermal analysis during mechanical testing reveal that a stress may be responsible for the variation of the latent heat of the transformation.

© EDP Sciences 2003