The Influence of Isothermal Loading-Unloading Cycles on Inelastic Properties of a TiNi-Based Alloy in the B2-Phase State During Bending Deformation.

Using Ti_49.3Ni_50.7 (at.%) alloy specimens, the influence of mechanical cycling by the bend method on the values of shape memory and superelasticity effects is investigated at the maximum given deformation in the interval from 4.0 to 22.8%. For every given value of the deformation, 11 mechanical cycles of loading and unloading are performed at T = 295 K, i.e., higher than A_f, in a tool set with a V-shaped channel (angle between the channel walls 90°) during loading of the specimens by the cylinders of a given radius. After every loading-unloading cycle, the specimens are heated to 493 K and the plastic deformation component is recorded. It is found out that even a small deformation of 4.5%, set for the Ti_49.3Ni_50.7 (at.%) alloy specimens in the В2-phase, gives rise to the formation of a plastic deformation component. The results presented in this study have to be taken into consideration in the practical applications of this alloy composition in the fabrication and use of the medical products subjected to stress and bending conditions. [ABSTRACT FROM AUTHOR]