Numerical Investigation in Nitinol Lattice Stability and Safe Usage in Replacing Hard Tissue

NiTi (also called Nitinol) transforms from cubic (austenite) to monoclinic (martensite), and vice versa, owing the shape memory effect superelasticity. Nitinol has a large number of biomedical applications because its low elastic modulus close that natural bone material good resistance corrosion fatigue, in addition transformation temperatures nitinol are body temperature. It many other important applications, such as aircraft industry. In all these especially medical stability is an factor for safety. Our goal study by calculating phonon dispersion relation obtain accurate understanding mechanically unstable phases alloy. The was studied coded using MATLAB make clear consideration optical acoustic branches. Moreover, density state energy lattice vibrations were calculated. crystal found be stable anharmonic part interactions. austenite phase up (300 K). While it not above Any extra due temperature changes caused martensite phase. positive modes indicate against perturbations. When thermal vibration calculated case at T= 300 K. both cases, less than 5 eV. There no broken bonds vibration.