2007 Volume 7 Issue 1 Pages 34-38
Shape recovery properties of a Ti-Ni alloy were experimentally studied. The Ti-Ni plate was curved to memorize a high temperature shape at 400°C,and then tensile stress was given for a low temperature shape memory at the room temperature. The three shape recovery patterns were obtained according to the tensile strains. In the PatternI, the normal shape recovery occurred at the tensile strain below 5%. In the PatternII, where the tensile strain was between 5% and 15%, the plate deforms opposite side before the normal shape recovery. In the PatternIII, there was only the opposite deformation without the normal shape recovery above 15% of the tensile strain. Behaviors of two way recovery with a heat cycle were different for the each pattern. The recovery ratio and bending force in these patterns were measured. The bending force and shape recovery ratio of the opposite deformation were smaller and larger than those of the normal shape recovery.
