Mechanical Properties of a Cu46Zr54 Bulk Metallic Glass with Embedded Nanocrystal Particles

AA MANELLI; F ARDIANI; C. J. RUESTES; D.R. TRAMONTINA; C CAREGLIO; E. M. BRINGA

Buenos Aires

Congreso; PanAmerican Congress on Computational Mechanics; 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 improvethe dynamics of plasticity, the composition of the metallic glasses is modified in different ways [1-3].Particularly, the inclusion of nanocrystals provides obstacles to SB propagation and growth, with SB oftennucleating at the interface between the BMG and the nanoparticle [1]. This results in a reduced and morehomogeneous deformation in the plastic regime. Nevertheless, to ensure lasting effects, the inclusionsshould be stable in time, i.e. not diffuse into the surrounding amorphous material loosing the sharptransition from crystal to amorphous. In previous work [5] we determined constitutive parameters of the Cu46Zr54 metallic glass as a function oftemperature, using atomistic Molecular Dynamics (MD) simulations. We will now present results for twodifferent types of inclusions: FCC copper and B2-CuZr sphere-shaped nanocrystals. Although we won'tfocus on the size effects of inclusions like other works [3-4], we analyse the stability of the nanoparticles atdifferent temperatures. During mechnical deformation of a BMG sample with inclusions, we analizeVoronoi polyhedra, and shear stress and shear strain localization to study the role of the inclusion in themechanical properties of this composite material.