Mechanism research on nanoscale circumferential repetitive friction and wear of the duplex full lamellar TiAl alloys

The duplex full lamellar (DFL) TiAl alloys are widely used in aerospace and other defense fields by virtue of their low density, creep resistance, oxidation resistance and exceptional mechanical properties at high temperatures, but there are still gaps in the research related to their friction and wear. In this paper, the friction response and mechanical properties during the friction process are systematically investigated by using molecular dynamics (MD) simulations in combination with tribological experiments at different temperatures. It has been found that the α 2 phase exhibits higher friction and friction coefficients with more drastic fluctuations. The friction force and friction coefficient at the interface (especially at the α 2 /γ interface) are greater than those of the single phase due to the complexity of the microstructure and the high shear strength. The α 2 phase leads to more severe wear scars (large increase in depth/width), roughness and wear rate due to its hard and brittle properties, while the γ phase enhances wear resistance through plastic deformation. It is also found that oxidative and abrasive wear are the main wear mechanisms, with the oxide layer and friction film directly affecting the way the material is removed and deformed. • The developed model can study frictional behavior of two phases and the interface. • Circumferential repetitive friction can systematically analyze subsurface damage. • Simulation combined with experiment provide more full insight into frictional wear. • Promote the engineering application of the duplex full lamellar TiAl alloys.