THE INFLUENCE OF THERMAL AND MECHANICAL TREATMENT ON THE REACTIVE STRESSES IN TINI SHAPE-MEMORY ALLOYS

The reactive stresses of the tensile prestrained specimens were invest igated in two hot rolled TiNi alloys. The alloy A containing 50,8 at % Ni exhibited pseudoelastic properties at the room temperature. The al loy B (49,5 at % Ni) had the martensitic structure at the room tempera ture. Part of the alloy B was further cold rolled with reduction of 15 % (C specimens). The reactive stresses are higher if the change (if th e shape is accompanied by the stress induced martensitic transformatio n (A specimens) in comparison with B specimens. The reactive stresses attained with C specimens are remarkably higher than those with A and B specimens.