Martensitic transformation of grain-size mixed Ti51Ni49 melt-spun ribbons

The as-spun and annealed ribbons of grain-size mixed Ti51N49 SMA exhibit the multiple martensitic transformations in which the annealed ribbons possess more obvious transformation peaks and less transformation hysteresis. According to the partial-cycled DSC test, transformation peaks are associated with B2 → R transformation, R→B191′R→B191′ transformation for large grains and R→B192′R→B192′ transformation for small grains during cooling, and B191′→B2B191′→B2 transformation for large grains and B192′→B2B192′→B2 transformation for small grains during heating.