Titanium Alloys: From Properties Prediction to Performance Optimization

Abstract

Like many structural materials, titanium alloys have complex multiscale hierarchical structures that enabled a variety of mechanical properties. The elastic modulus, strength, ductility, fatigue, and creep behavior may depend strongly on the multiscale structures, from the bonding between atoms, to microstructures up to grain level, and their texture. However, their interdependences are usually not straightforward and sometimes not easy to reveal solely by experiments. Multiscale modeling and simulation in the last two decades have promoted the understanding of various aspects of titanium alloys. The progresses range from electronic structural calculation of alloying effects on modulus, strength, ductility, creep and oxidation, etc., to the ordering behavior in intermetallic phases and interaction between alloying elements and dislocation or twinning; atomic simulations of dislocation interaction and point defect formation, deformation and fracture mechanisms of polycrystalline titanium with grain boundaries of different nature under various stress; phase transformation and microstructure evolution under different conditions, and the effects of internal and external factors on the microstructure evolution and mechanical behavior of titanium alloys; finally FEM type simulations to optimize the thermo-mechanical processing, such as rolling and canned extrusion, etc. In spite of the increasing capabilities of multiscale materials modeling and simulation, many challenges still exist, and further seamless interdisciplinary collaborations among materials scientists, system designers, and industry production sections are needed to solve the grand challenge of the overall optimization of the titanium alloys for specific applications.