Atomic simulations of melting behaviours for TiAl alloy nanoparticles during heating

Abstract

Titanium alloys not only have a high strength to weight ratio and good corrosion resistance but also have a higher cost on traditionally metallurgy. In additive manufacturing (AM) process, the thermal stability of alloy particles during heating has an important influence on fabricating parts. This article presents atomic simulations to study changes of packing structures and atomic level stresses by using a molecular dynamics (MD) approach within the framework of embedded atom method (EAM). This research provides different evolution patterns of TiAl nanoparticles with different sizes owing to the following facts that the atoms undergo different strain states. In these particles, a large proportion of Al atoms are subjected to tensile or compressive strain, whereas a considerable number of Ti atoms are stretched or compressed only at high temperatures. Back propagation neural network is used to calculate data of specific heat, and the machine learning provides the possibility to determine critical size suitable for the classical Dulong–Petit law under certain thermal conditions.