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Based on analysis of embedded atom potential molecular dynamics simulation of the body-centered cubic and face-centered cubic two kinds of nano-metal materials under different loading mechanical properties, while also of temperature, size and strain rate on mechanical properties effects. From the stress - strain curves, atomic position changes diagram explains the mechanical properties of nanomaterials produced. On nano-Mo wire BCC structure studies show that: in the tensile load, and slip dislocations nanowire deformation mechanism is the main reason for the formation of vacancies from the surface atoms begin, with the continuous expansion of the last defect caused the fracture of nano . At a temperature range from 100K to 500K, as the temperature increases, the aluminum crystal nanowires tensile yield stress decreased, increasing the fracture stress; yield strain decreases, fracture strain 300K at room temperature reaches the maximum . In addition, 100K and 300K, the nanowire structure during the tensile yield deformation there is a clear internal deformation to slip dominated; at 500K, no apparent yielding, irregular arrangement of atoms into a state of disorder , mixed with the internal structure of a large number of dislocations and slip phenomenon. Nanowires of different sizes The simulation results show that the elastic deformation stage, as the size increases, the stress - strain curve of a clear distinction between no deformation; into nano-stretched plastic deformation, size effect becomes more and more Clearly, as the size increases, yielding the area becomes more narrow, the required yield strain decreased gradually, but a gradual increase in the yield strength. In the simulation of different strain rates, as the strain rate increases, the yield strength and fracture strength are increased. FCC structure of nano-Ag wire studies show that: for crystal nanowires, in the drawing process, in terms of deformation model of atomic structure, the internal structure mainly slip on both sides with some dislocations appear stacking phenomenon, the upper and lower ends at a distance of nanowires about 1/3 at the emergence of multiple necking. The polycrystalline nanowires stretching process, the nanowire in the elastic deformation stage, the nanowire appears multiple times yielding stress increases as the strain was \, the stress strain curve increases rapidly with the rise, and then there was a break yield platform. With the increase in the stress strain rapid decline, this time nanowires showed significant superplasticity. Different structures of nano metal material in a stretching process, BCC nanowires earlier than the FCC nanowires into elastic deformation stage, BCC nanowires lower than the FCC dense nanowires, but there is a better ductility. In the elastic deformation stage and plastic deformation phases have almost equal strain interval is less than the yield strength tensile strength, ductility nanowires showed a stronger; relative to the BCC nanowires, while the FCC nanowire based mainly on elastic deformation, but only elastic deformation strain occupies the entire load 1/4, into the plastic deformation, the atomic mechanism model appeared quickly necking and begin to break, breaking strength greater than the yield strength. In the atomic structure in terms of deformation, BCC structure nanowire from the surface destruction, the atomic model of surface deformation and internal dislocation slip based, and a small amount of stacking now, finally, from the middle of the neck nanowires shrinkage phenomenon, began to break; while the FCC structure of nano internal structure from the beginning a lot of slippage occurs, there are different degrees of surface defects in the atomic structure of the main deformation to slip, and finally two 1/3 appears a double necking.
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