Experimental investigation and thermodynamic calculation of the Ti-Ni-Cu shape memory alloys

• The effect of Cu content on the thermoelastic martensitic transformation in TiNi shape memory alloys (SMAs) was systematically investigated by means of differential scanning calorimetry (DSC). Martensitic transformation temperatures and transformation enthalpy were measured for a series of alloys with composition Ti50Ni50-xCux (x = 0 to 13 at. pet). The measured data were then used to evaluate the thermodynamic properties of the low-temperature orthorhombic B19 and monoclinic B19' phases using a two-sublattice model (Ni, Cu, Va)(0.5)(Ni, Cu, Ti)(0.5) in combination with the thermodynamic description of the parent B2 phase. The vertical section of the pseudobinary TiNi-TiCu was calculated including the B19 and B19' phases. Transformation enthalpy and stress rate were predicted for the ternary TiNiCu SMAs, which are in reasonable agreement with experimental data.

Nyckelord

thermoelastic martensitic transformations

system

phase

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)