Characterization of a rapidly annealed Ti50Ni25Cu25 melt-spun ribbon

In the present paper, crystallization behavior, martensitic transformation and deformation behavior of a Ti50Ni25Cu25 ribbon annealed at 400 °C under rapid heating were studied. The initially amorphous ribbon was fully crystallized under rapid thermal annealing at 400 °C for 30 s. However, under conventional thermal annealing, crystallization temperature was above 450 °C. The crystallization at low temperature under rapid heating was attributed to the release of the extra energy due to the annihilation of free-volume in amorphous state. With increasing the annealing time, martensitic transformation temperatures increased. The ribbon annealed at 400 °C for 300 s has developed good shape recovery properties. A 2.7% one-way memory strain was obtained the tensile strain of 5.5%. The deformation behavior showed non-flat stress-plateau and high spring-back, which is discussed in terms of grain size and orientation distribution of martensite variants.