Formation of the Ni--Zr--Al Ternary Metallic Glasses Investigated by Interatomic Potential through Molecular Dynamic Simulation

Under the framework of second moment approximation of the tight binding theory, a realistic interatomic potential is first developed for the Ni--Zr--Al ternary metal system and then applied to predict the glass-forming ability of the system through molecular dynamics simulation. It is found that when the composition falls into the hexagonal region defined by six vertexes of Ni20Zr80Al0, Ni0Zr65Al35, Ni0Zr25Al75, Ni20Zr0Al80, Ni40Zr0Al60, and Ni77Zr23Al0, the super-saturated solid solution becomes unstable and spontaneously turns into the disorder state, i.e., the metallic glass state. The defined composition region could be considered as a quantitative glass-forming ability, within which the Ni--Zr--Al ternary metallic glass is predicted to be energetically favored to form. Interestingly, the prediction based on the interatomic potential matches well with experimental observations.