Diffusion in Ni-Based Single Crystal Superalloys with Density Functional Theory and Kinetic Monte Carlo Method. (31st August 2016)

• Record Type: Journal Article
• Authors: Sun, Min; Li, Zi; Zhu, Guo-Zhen; Liu, Wen-Qing; Liu, Shao-Hua; Wang, Chong-Yu
• Is Part Of: Communications in computational physics. Volume 20:Number 3(2016:Sep.)
• Page Start: 603
• Page End: 618
• Publication Date: 2016-08-31
• Subjects: 71.15.Mb, -- 61.43.Bn, -- 66.30.-h, -- 71.55.Ak; Diffusion behavior, -- transition rate, -- density functional theory, -- kinetic Monte Carlo method, -- superalloy; Mathematical physics -- Data processing -- Periodicals; Physics -- Data processing -- Periodicals; 530.150285
• DOI: 10.4208/cicp.111115.271115a
• Languages: English
• ISSNs: 1815-2406

Abstract

Abstract: In the paper, we focus on atom diffusion behavior in Ni-based superalloys, which have important applications in the aero-industry. Specifically, the expressions of the key physical parameter – transition rate (jump rate) in the diffusion can be given from the diffusion theory in solids and the kinetic Monte Carlo (KMC) method, respectively. The transition rate controls the diffusion process and is directly related to the energy of vacancy formation and the energy of migration of atom from density functional theory (DFT). Moreover, from the KMC calculations, the diffusion coefficients for Ni and Al atoms in the γ phase (Ni matrix) and the γʹ phase (intermetallic compound Ni3 Al) of the superalloy have been obtained. We propose a strategy of time stepping to deal with the multi-time scale issues. In addition, the influence of temperature and Al concentration on diffusion in dilute alloys is also reported.