ATOMISTIC STUDY OF THE MECHANICAL PROPERTIES OF A SINTERED BULK METALLIC GLASS (NANOGLASS)
F Ardiani and AA Manelli and CJ Ruestes and CA Careglio and EM Bringa, PROCEEDINGS OF THE 1ST PAN-AMERICAN CONGRESS ON COMPUTATIONAL MECHANICS AND XI ARGENTINE CONGRESS ON COMPUTATIONAL MECHANICS, 156-165 (2015).
Metallic glasses with porosity have been in the spotlight in recent years and much research has been done on them, in an effort to improve the understanding of the mechanics of deformation. The behavior of the material in the elastoplastic regime may be controlled by the introduction of pores, thus the interest on simulating them. Large deformation is normally a consequence of shear transformations zones (STZ) collapsing into shear bands (SB) which may lead to catastrophic failure. It is widely known that in crystalline metals the addition of nanopores slows down dislocation motion and changes the resulting plastic deformation. Similarly, pores in metallic glasses limit the propagation of shear bands and allow a more homogeneous deformation. In previous work we determined constitutive parameters of the Cu46 Zr54 metallic glass as a function of temperature. We now present results for a metallic glass with the same composition, but fabricated by sintering of BMG nanoparticles, which results in samples with porosity, similar to nanoglass samples in some experiments and simulations. Atomistic simulations arc carried out using Molecular Dynamics (MD), and analysis includes atomic Voronoi polyhedra, and atomic stress and strain. We analyse the dependence of deformation on solid volume fraction, and the way deformation is distributed throughout the sample, as a function of initial porosity.
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