Effect of Length and Cross-Sectional Area on Ni3Fe Alloy Plasticity

Abstract

Molecular Dynamics (MD) simulations have been carried out on ultrathin Ni3Fe alloy with face-centered cubic (FCC) lattice upon application of uniaxial tension at nanolevel with a speed of 20 m/s. the deformation corresponds to the direction <001>. To the calculated block of crystal - free boundary conditions are applied in the directions <100>, <010>. Morse potential was employed to carry out three dimensional molecular dynamics simulations. A computer experiment is performed at a temperature corresponding to 300 K. MD simulation used to investigate the effect of long of ultrathin Ni3Fe alloy on the nature of deformation and fracture. The engineering stress–time diagrams obtained by the MD simulations of the tensile specimens of these ultrathin Ni3Fe alloy show a rapid increase in stress up to a maximum followed by a gradual drop to zero when the specimen fails by ductile fracture. The feature of deformation energy can be divided into four regions: quasi-elastic, plastic, flow and failure. The yield strength decreased with increasing long of alloy, but increases with increasing the cross sectional area. Plasticity disappear when the length of the allays is too large. The results showed that breaking position depended on the alloy length.