J. Phys. IV France
Volume 112, October 2003
Page(s) 1111 - 1114

J. Phys. IV France
112 (2003) 1111
DOI: 10.1051/jp4:20031077

Pseudotwinning in indium-lead concentrated alloys

L.S. Fomenko, S.V. Lubenets and V.D. Natsik

Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 47 Lenin Ave., Kharkov 61103, Ukraine

Pseudoelasticity caused by pseudotwinning in short-range ordered In-Pb alloys (6, 8 and 11.6 at.% Pb) is studied in the temperature range 1,7-180 K. The mechanical hysteresis parameters, namely, the thermodynamic stress $\tau_{\rm T}$ which provides the reversibility of plastic deformation and the friction stress $\tau_{\rm f}$ which characterizes the resistance offered by crystal lattice and its defects to twin boundaries motion are estimated. It is found that athermal processes determine the reversible deformation: the mechanical parameters $\tau_{\rm T}$ N $\tau_{\rm f}$ do not depend on temperature and strain rate. The stress $\tau_{\rm T}$ increases and the stress $\tau_{\rm f}$ decreases with increasing Pb content. One of the main conditions of the exhibition of superelasticity is the fulfillment of the inequality $\tau_{\rm T}> \tau_{\rm f}$.

© EDP Sciences 2003