The mechanical cycling behavior of TiNi based crystal/glassy alloy in the superelastic mode

We designed TiNi bulk metallic glass composite (BMGC) which has both a glassy phase and a crystalline phase. The TiNi BMGC undergoes a martensitic transformation during deformation, exhibits the superelastic behavior and excellent mechanical properties: strength of 2.5 GPa, ductility of more than 20%. It is known that mechanical-fatigue is an important feature which affects the martensitic transformation during superelastic cyclic loading. Comparison of the fatigue performances in TiNi dual-phase alloy and TiNi fully crystalline alloy demonstrates that the amorphous phase acts as the barrier and sinking of the dislocation slipping and promotes martensite-austenite phase transition during the superelastic cycling. The representative BMGCs provide a way to design metallic glasses with high ductility and outstanding anti-fatigue properties.