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

Abstract

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 Ni Al 0 , 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-ZrAl ternary metallic glass is predicted to be energetically favored to form. Interestingly, the prediction based on the interatomic potential matches well with experimental observations.

Chemical and topological short-range orders in the ternary Ni–Zr–Al metallic glasses studied by Monte Carlo simulations

“…Based on three empirical rules which were proposed by Inoue et al [3], the ternary Ni-Zr-Al metal system should exhibit high glass-forming ability (GFA) as a result of the large atomic size difference and strong negative interaction between constituting elements. In the previously published work [5], amorphous alloys are predicted by molecular dynamics (MD) simulations to be formed in wide compositional ranges, and these predictions are supported by abundant experimental observations.…”

“…Based on the constructed Ni-Zr-Al [5] n-body potentials, Monte Carlo simulations are then performed with the isothermal-isobaric ensemble (details can be referred to in [24]). The initial simulation box is constructed to be an fcc or hcp structure according to which type (fcc for Ni-based/Al-based or hcp for Zr/Ti-based) of atoms is dominant in the composition for a given alloy [23,25,26].…”

“…The solvent atoms were then substituted randomly by a certain number of solute atoms to form a random solid solution with the desired chemical composition. The reproduced lattice constants of pure Ni, Al and Zr have been obtained by the constructed Ni-Zr-Al [5] n-body potentials. For the fcc or hcp solid solutions, the lattice parameters were then initially set according to Vegard's law and fully relaxed at 300 K and zero pressure through MC simulations.…”

“…Atomic-scale packing orders obtained from experimental and computational efforts are very useful for extracting atomic packing principles and structural concepts, and should eventually lead to an improved understanding of properties such as the stability and plasticity of BMGs. In the present work, based on the constructed and proven realistic n-body potential of the Ni-Zr-Al [5] system, Monte Carlo simulations were carried out to investigate atomic-scale structural evolutions associated with metallic glass formation in these ternary systems. To examine the short-range orders formed during the crystal-to-amorphous phase transition, the micro-chemical inhomogeneity (MCI) parameter ξ and Honeycutt and Anderson (HA) pair analysis have been applied to characterize the CSROs and topological short-range orders for ternary alloys in the Ni-Zr-Al system, respectively.…”

Formation and Structure of Pd–Zr Metallic Glasses Studied by Molecular Dynamics Simulations

“…12,13) As a candidate for BMGs, the Zr-based alloy system has been of particular interest due to its high GFA and extremely wide super-cooled liquid regions. 2,[14][15][16] For the Pd-Zr system, although it has been studied for phase preparation and structural analysis, reports on computer simulations have been much less extensive than those with many commercial applications. [17][18][19][20] For instance, Robert et al presented the results of a study of the hydrides of Zr 65 Pd 35 and Zr 67 Pd 33 metallic glasses.…”