Abstract
Loading-unloading atomic simulations of an amorphous metal which is obtained by a molecular dynamics simulation for the melting-rapid quenching process are performed in order to obtain the fundamental mechanical properties and the changes of mechanical properties and atomic structures. The metastable structures which are created by large preloading exceeding the maximum loading point are more unstable than the initial amorphous structure. The elastic moduli decrease by the large preloading. The decrease is not explained by the volume average of individual atomic elastic moduli in the inhomogeneous deformation of internal atomic structure. However, by dealing the amorphous structure as a heterogeneous elastic body and carrying out a Finite Element Analysis, the solution shows the tendency of decrease in elastic moduli. The strength, which is evaluated by yield stress as the maximum stress, also decreases by preloading and its anisotropy appears. The strength in hydrostatic compression is larger than that in tension. These changes of mechanical properties by preloading are closely related to the destruction of intrinsic clusters composed of 13 atoms, which is viewed as the number of icosahedra by Voronoi polyhedra analysis.
