Structural Change of TiAl Alloy under Uniaxial Tension and Compression in the <001> Direction: A Molecular Dynamics Study

Abstract

TiAl alloys can be used in aircraft and high-performance vehicle engines owing to their structural stability at high temperatures and their light weight. Although many studies have focused on developing this alloy material, there is still a lack of information about the changes in the structure of TiAl alloys under tensile and compressive loading. Therefore, we performed molecular dynamics simulations of the tensile and compressive loading of TiAl alloys in the &lt;001&gt; direction at temperatures of 10 and 300 K. From our simulation results, we found that the tensile and compressive strengths of TiAl alloys are significantly affected by temperature. It was found that TiAl alloys can withstand greater compression loading than tensile loading. This is due to the change in the crystal structure of TiAl alloys after being deformed to a strain of 0.4 by compressive loading, according to the analysis of structural changes under loading conditions. From the radial distribution analysis results, there was a change in the orientation of the face-centered cubic-like structure as it reached the maximum compressive stress compared to the initial structure.

Atomic-Scale Dislocation Structure Evolution and Crystal Ordering Analysis of Melting and Crystallization Microprocesses in Laser Powder Bed Melting of γ-TiAl Alloys

“…sandia.gov) [33] and microscopic particle evolution algorithm, the microscopic evolution process for the melting and crystallization of γ-TiAl alloy in LPBF process was constructed. Differing from the regular FCC lattice structure, γ-TiAl alloy exhibits the ordered L 10 facecentered tetragonal (FCT) structure, where the (002) plane is alternately occupied by Ti and Al atoms [34][35][36][37]. The initial configuration of the laser powder bed fusion experiment is outlined in Table 1.…”

Growth and Deformation Simulation of Aluminum Bronze Grains Produced by Electron Beam Additive Manufacturing

“…Using eight simulated layers as an example, it is shown that a low cooling rate leads to a decrease in the number of defects, and also that defect-free single crystals are printed up to the critical layer thickness. The results [31] of MD simulation of the TiAl alloy deformation behavior under tension and compression at temperatures of 10 and 300 K show a significant temperature dependence associated with the crystal structure.…”