The Construction Of NiTi Alloy Interatomic Potentials

In recent years, NiTi alloy has been widely used as functionalmaterials in the industrial,such as biomedical and mechanicaldevices,because of its special shape memory and superelastic properties.The unique properties of the NiTi alloy is mainly due to the reversibleartensitic transformation of the alloy memory between the hightemperature B2phase and the low-temperature B19’ phase, the B19phaseor R phase. Now many researchers have studied on the martensitictransformation haracteristics of NiTi alloy,in order to enhance theperformance of the alloy required.The research object is the NiTi alloy, and we use the model ofEmbedded Atom Method potential for the potential of Ni, Ti and NiTialloy. The main content is that construct the Ni, Ti and B2type NiTialloy interatomic EAM potential by using the lattice constants of themetal, binding energy, no relaxation of the vacancy formation energy,elastic constants and the anisotropy ratio of the experimental data asinput parameters.In order to study the NiTi alloy at the atomic level.Compared with Rose curve to validate the reliability of potential,and the results showed that the two curves are very close. In addition, dueto the truncation distance of the potential function has a greater impact onthe performance of the potential function, in this thesis, the potentialfunction truncation processing, respectively, calculated combination ofmetal Ni, Ti and NiTi alloy, results show that the binding energycalculation agrees well with the experimental values. Calculation of themetal Ni, Ti and NiTi alloy single vacancy formation energy, the verysmall difference with the experimental values. At the same time, we alsodiscuss the structural stability of the NiTi alloys, and the calculated results show that: NiTi alloy of bcc structure should be stable than the fccand hcp structure, consistent with the facts.