First-principles study on alloying effect on martensitic transformation behavior of TiNi alloy

The alloying effect on the martensitic transformation behavior of TiNi alloy is investigated for the first time from the elastic properties and electronic structure by the plane-wave pseudopotential method within the local density approximation. The elastic constants and density of states are calculated. The results show that the alloying effect on the martensitic transformation behavior of TiNi alloy is close related to its elastic properties. The Ti d density of states at Fermi level is mainly responsible for the B2 phase stability of TiNi alloy with the low addition of the third element. As for TiNiPd ternary alloy, the high martensitic transformation temperature stems from the stabilization of B19 phase TiNiPd by the high addition of Pd content.