Formation mechanism of γ twins in β-solidified γ-TiAl alloys

Defects, such as stacking faults (SF) and twins, play a crucial role in stabilizing the order phase and improving the mechanical properties for engineering alloys. The formation mechanism of the γ twins from α2-platelets within β0 areas was analyzed at atomic-scale by atomic-resolution high-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM). The growth faults (ABAB˙CBC) were formed in α2-platelets, yielding a local...