title: Study of deformation and shape recovery of NiTi nanowires under torsion.
abstract: The nanomechanical properties, deformation, and shape recovery mechanism of NiTi nanowires (NWs) under torsion are studied using molecular dynamics simulations. The effects of loading rate, aspect ratio of NWs, and NW shape are evaluated in terms of atomic trajectories, potential energy, torque required for deformation, stress, shear modulus, centro-symmetry parameter, and radial distribution function. Simulation results show that dislocation nucleation starts from the surface and then extends to the interior along the {110} close-packed plane. For a high loading rate, the occurrence of torsional buckling of a NW is faster, and the buckling gradually develops near the location of the applied external loading. The critical torsional angle and critical buckling angle increase with aspect ratio of the NWs. Square NWs have better mechanical strength than that of circular NWs due to the effect of shape. Shape recovery naturally occurs before buckling.
authors: Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan.
authors: Cheng-Da
authors: CD
authors: Wu
authors: Po-Hsien
authors: PH
authors: Sung
authors: Te-Hua
authors: TH
authors: Fang
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D055119:Elastic Modulus; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D053770:Nanowires / Q000737:chemistry*; D011789:Quantum Theory; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013816:Thermodynamics
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; C013616:nitinol