Effect of Ti Additions on Mechanical and Thermodynamic Properties of W-Ti Alloys: A First-principles Study
摘要
The mechanical and thermodynamic properties of W-Ti alloys ( including W15Ti1, W14Ti2, W12Ti4 and W8Ti8 alloys) were investigated by the first-principles approach based on density functional theory. The results indicate that W-Ti alloys except W8Ti8 are thermodynamically stable. The modulus and hardness of W-Ti alloys are smaller than those of pure tungsten and gradually decrease with increasing Ti concentration. However, their B/G ratios and Poisson’s ratios exceed those of pure tungsten, suggesting that the introduction of Ti decreases the mechanical strength while enhancing the ductility of W-Ti alloys. The thermal expansion coefficients for W-Ti alloys all surpass those of pure tungsten, indicating that the introduction of titanium exacerbates the thermal expansion behavior of W-Ti alloys. Nevertheless, elevated pressure has the capacity to suppress the thermal expansion tendencies in titanium-doped tungsten alloys. This study offers theoretical insights for the design of nuclear materials by exploring the mechanical and thermodynamic properties of W-Ti alloys.