Charge optimized many-body (COMB) potential for dynamical simulation of Ni–Al phases. (26th August 2015)

• Record Type: Journal Article
• Authors: Kumar, Aakash; Chernatynskiy, Aleksandr; Liang, Tao; Choudhary, Kamal; Noordhoek, Mark J; Cheng, Yu-Ting; Phillpot, Simon R; Sinnott, Susan B
• Is Part Of: Journal of physics. Volume 27:Number 33(2015)
• Page Start: 682
• Page End: 694
• Publication Date: 2015-08-26
• Subjects: Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/33/336302
• Languages: English
• ISSNs: 0953-8984

Abstract

<abstract> <title>Abstract</title> <p>An interatomic potential for the Ni–Al system is presented within the third-generation charge optimized many-body (COMB3) formalism. The potential has been optimized for Ni<sub>3</sub>Al, or the <italic>γ</italic>′ phase in Ni-based superalloys. The formation energies predicted for other Ni–Al phases are in reasonable agreement with first-principles results. The potential further predicts good mechanical properties for Ni<sub>3</sub>Al, which includes the values of the complex stacking fault (CSF) and the anti-phase boundary (APB) energies for the (1 1 1) and (1 0 0) planes. It is also used to investigate dislocation propagation across the Ni<sub>3</sub>Al (1 1 0)–Ni (1 1 0) interface, and the results are consistent with simulation results reported in the literature. The potential is further used in combination with a recent COMB3 potential for Al<sub>2</sub>O<sub>3</sub> to investigate the Ni<sub>3</sub>Al (1 1 1)–Al<sub>2</sub>O<sub>3</sub> (0 0 01) interface, which has not been modeled previously at the classical atomistic level due to the lack of a reactive potential to describe both Ni<sub>3</sub>Al and Al<sub>2</sub>O<sub>3</sub> as well as interactions between them. The calculated work of adhesion for this interface is predicted to be 1.85 J m<sup>−2</sup>, which is in agreement with available experimental data. The predicted interlayer distance is further consistent with the available first-principles results for Ni (1 1 1)–Al<sub>2</sub>O<sub>3</sub> (0 0 0 1).</p> </abstract>