Study of atomic-scale wear characteristics of a dual-phase TiAl alloy at different vibration frequencies

Abstract

Duplex titanium-aluminum alloys have significant advantages in terms of mechanical properties, lightweight potential, and application prospects, and have become one of the important materials for key components in the aerospace field. A deeper understanding of the mechanisms of vibration friction wear behavior close to real operating conditions is essential. The mechanical characteristics, atomic displacements, shear stresses, and dislocation densities of γ/α₂ biphasic TiAl alloys are examined in this work using molecular dynamics simulations at various vibration frequencies. It has been found that the greater the frequency of vibration, the smaller the total force on the substrate. Furthermore, the two-phase interface under friction at differing vibrational frequencies can significantly impede atomic motion. The friction process with a high vibrational frequency efficiently suppresses the anisotropic stress state, increasing the anisotropy of atomic motion. Increased vibration frequency raises the temperature of the friction region, which can lead to a softening effect that favors material removal. The microstructure evolution shows that many dislocations accumulate in the γ-phase. Higher vibration frequencies generate more defects, increasing dislocation density and the likelihood of plastic deformation in the material.