Stress-induced α″ martensitic (110) twinning in β-Ti alloys

A fully transformed α″ martensite with stress-induced nanoscale {110}, {021}-type compound twin or a 90° rotation twin has been experimentally explored and unambiguously characterized in traditional β-type Ti alloys, which usually undergo a partial martensitic transformation [a β grain partially transformed into α″ with internal (111) twin] by quenching. This newly observed twinning, which matches with the predication based on the deformation twinning theory of Bilby and Crocker [Proc. R. Soc. 288, 241 (1965)], can help to explain the deformation mechanism and aid future development of advanced materials.