Investigating local atomic structural order in TiAl3 metallic glass using molecular dynamic simulation

In this work, we studied structural properties of super cooled binary TiAl3 metallic glass (MG) using molecular dynamics (MD) simulation in the framework of embedded atom method (EAM). The atomic local structure is analyzed using the radial distribution function (RDF), the common neighbors analysis technique (CNA), the coordination numbers (CNs), and the Voronoi tessellation analysis (VTA). The glass transition temperature Tg is determined using the Wendt-Abraham method. The results showed that during the high-rate cooling process the volume decreases continuously with a slight slope change leading to the glass formation. The glass transition temperature Tg increases with the increasing cooling rate. The radial distribution function linked the split of the second peak of the different pair distribution functions to icosahedral polyhedra, The glass formation follows the spherical-periodic order (SPO) except for the third peak R3/R1 = 4, which correspond to the local translational symmetry (LTS) contributing to the connection of polyhedra as vertex-sharing mode (VS). Partial RDF of icosahedral-like, mixed and others coordinated VPs revealed that the metallic glass structure is not due mainly to the perfect icosahedral unit but also to others icosahedral-like and mixed VPs with clusters coordinated from CN11 to CN15. In particular, Al centered clusters assemble more VPs indexed as <0,0,12,0> and <0,1,10,2> and Ti centered clusters try to form fewer but larger polyhedra such as <0,0,12,2> and <0,0,12,3>.