The Mixing Enthalpy and Liquid Structural Properties of Ti–Al Alloys by ab inito Molecular Dynamics Simulation.

The mixing enthalpy and structural properties of liquid Ti–Al alloys are investigated by ab inito molecular dynamics simulation at 2033 K. The experimental mixing enthalpy is well reproduced in both magnitude and asymmetric behavior. Based on the subregular solution model, the interaction strength between unlike atoms on the Al-rich side is about 50% stronger than that on the Ti–rich side, and the minimum of mixing enthalpy is located around 55 at.% Ti. The partial coordination numbers are provided to understand the chemical short-range order of such model. A linear interpolation of bonded pairs versus concentration is employed to elucidate the local structural evolution. Coupling of self-diffusion coefficients of Ti and Al atoms on Ti–rich side is broken et al.-rich side due to the enhancement of structural disorder. [ABSTRACT FROM AUTHOR]