Polymorphic nature of {332} 〈 113 〉 twinning mode in BCC alloys

Unprecedented mechanical properties of the novel TWIP/TRIP titanium alloys are controlled by {332}<113> twinning and stress-induced martensitic transformation, which can operate separately, simultaneously or even in synergy, following a still unclear atomic-scale mechanism. Using ab initio calculations experimental observations, we show that be described as polymorphic solid-state transformation able to produce either twinned structures with unified path. The required lattice strains atomic shuffles provided shear-shuffle mechanism twin operation, trajectory, due accompanied relaxation, is not linear strongly influenced β phase stability.