MECHANICAL PROPERTIES OF A CU(46)ZR(54) BULK METALLIC GLASS WITH EMBEDDED CRYSTALLINE NANO PARTICLES
AA Manelli and F Ardiani and CA Careglio and EM Bringa, PROCEEDINGS OF THE 1ST PAN-AMERICAN CONGRESS ON COMPUTATIONAL MECHANICS AND XI ARGENTINE CONGRESS ON COMPUTATIONAL MECHANICS, 166-176 (2015).
Plasticity in bulk metallic glasses (BMGs), is normally dominated initially by shear transformations zones (STZ), which expand to form shear bands (SB) through the material. In order to control and thus improve the dynamics of plasticity, composition of metallic glasses has been modified in different ways. Particularly, the inclusion of crystalline nanoparticles provides obstacles to SB propagation and growth, with SB often nucleating at the interface between the BMG and the nanoparticle. This results in a reduced and more homogeneous deformation in the plastic regime. Nevertheless, to ensure lasting effects, inclusions should be stable in time, i.e. not diffuse into the surrounding amorphous material loosing the sharp transition from crystal to amorphous. In previous work we determined constitutive parameters of the Cu46Zr54 metallic glass as a function of temperature, using atomistic Molecular Dynamics (MD) simulations. We will now present results for spherical face-centered cubic (FCC) Cu inclusions. Although we do not focus on the size effects of inclusions like other studies, we analyze the stability of the nanoparticles at different temperatures. During mechanical deformation under uniaxial strain of a BMG sample with inclusions, we analyze Voronoi polyhedra, and shear stress and shear strain localization to study the role of the inclusion in the mechanical properties of this composite material.
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