Effect of Ni-reinforcement size on mechanical properties of Al metallic glass matrix from molecular dynamics

Abstract

We study the mechanical behavior of Aluminum metallic glass (Al-MG) and Al-based matrix nanocomposites (NCs) using molecular dynamics (MD) simulations within the framework of the Embedded Atom method (EAM). In terms of mechanical properties, metallic glass (MGs) are characterized by high performance, such as high yield strength and high strength, long-range atomic order is the main feature that links these mechanical properties to the structure of MGs. In the present work, the atomic structural characteristic of Al-MG is studied via several quantities such as radial distribution function (RDF), Voronoi tessellation analysis (VTA) and coordination number distribution (CN). Generally, the splitting of the second RDF peak during quenching confirmed the formation of Al-MG. The results of the application of a uniaxial tensile stress on the Al-MG samples and the NCs at 300 K with a strain rate of the order of $5.10{}^8{s}^{-1}$ showed that the mechanical properties (Young's modulus, ultimate tensile strength, elastic limit, etc.) are improved by the reinforcement of the Al-MG matrix with fibers (cylinder) of crystalline nickel compared to that of -monatomic Al-MG. In general, it is observed that the ultimate tensile strength and Young's modulus increase with the increase in the diameter of the reinforcing fibers. This is explained by the presence of the heterogeneous interface, which acts as a barrier to the propagation of shear bands and the atomic adjustment between Al and Ni stops the sliding and dislocations of the crystal planes.