Crystal-plasticity model of TiAl alloys incorporating deformation twinning

Key Points

• The aim is to understand the role of deformation twinning in coordinating plastic deformation in TiAl alloys.
• Developed a strain gradient crystal plasticity model incorporating dislocation slip and deformation twinning mechanisms.
• Considered twin nucleation, expansion, and growth processes alongside necessary dislocation density evolution.
• Analyzed compressive deformation behavior of near γ TiAl alloys at room temperature.
• The model accurately predicts yield strength and work hardening behavior of the alloys.
• Successfully captures stress relaxation characteristics caused by twin nucleation and rapid expansion.
• Shows that deformation twinning significantly alleviates local stress concentrations at grain boundaries.