First-principles study of ß-titanium alloy TiX (X=Al, Ni, Fe) for key parts of automobile engines

Abstract

As we all know, titanium alloys have excellent comprehensive mechanical properties, such as high ductility, rigidity, and density, which are superior to aluminium alloys. However, due to their high price, titanium alloys have not been able to be used in automobile engine bodies, but on small engine components, such as titanium alloys have been well used in connecting rods, valves, engine exhaust systems and fasteners. This article uses a new alloy design concept to design a new beta titanium alloy, hoping that it may be applied to small parts of automobile engines. Based on the density functional theory, the first-principles calculation method was used to study the structure and stability, formation heat, binding energy and elastic properties of TiX (X = Al, Ni, Fe) ß titanium alloy. The results show that these types of ß titanium are structurally and mechanically stable. By using Voigt-Reuss-Hill (VRH), the theoretical elastic constants Cij, bulk elastic modulus B, shear modulus G, Young's modulus E, Poisson's ratio ? of these ß titanium alloys are further obtained. The ductility and plastic toughness of these kinds of ß titanium alloys are analysed, and the ß titanium alloy system with excellent comprehensive performance is determined, which also provides a basis for the next element selection of the ß titanium alloy system for automobile engines.