Computer simulation of the elastically driven migration of a flat grain boundary
نویسندگان
چکیده
This paper describes a strategy for the measurement of boundary mobility using molecular dynamics (MD) simulations and its application to the migration of nominally flat h001i tilt grain boundaries in nickel, as described using an EAM potential. Determination of the driving force for boundary migration requires proper accounting for non-linear elastic effects for strains of the magnitude needed for MD simulation of stress-driven boundary migration. The grain boundary velocity was found to be a nonlinear function of driving force, especially at low temperature. However, extrapolation of the data to small driving force allows for the determination of the mobility at all temperatures. The activation energy for grain boundary migration was found to be 0.26 eV. This demonstrates that boundary migration in pure metals is not athermal, but the activation energy is much smaller than expected based upon experimental measurements. This discrepancy is similar to that found in earlier simulation measurements. 2004 Published by Elsevier Ltd on behalf of Acta Materialia Inc.
منابع مشابه
A phase-field model of stress effect on grain boundary migration
We developed a phase-field model to study the stress-driven grain boundary migration in elastically inhomogeneous polycrystalline materials with arbitrary elastic inhomogeneity and anisotropy. The dependence of elastic stiffness tensor on grain orientation is taken into account, and the elastic equilibrium equation is solved using the Fourier spectral iterative-perturbation method. We studied t...
متن کاملVacancy Generation During Grain Boundary Migration
We present a molecular dynamics simulation study of vacancy generation and emission from grain boundaries during curvature-driven grain boundary migration. The U-shaped half-loop bicrystal geometry is employed in order to maintain a constant driving force during boundary migration. Nonlinearities in plots of half-loop grain area versus time indicate the onset of non-steady-state behavior and va...
متن کاملA Data-driven Method for Crowd Simulation using a Holonification Model
In this paper, we present a data-driven method for crowd simulation with holonification model. With this extra module, the accuracy of simulation will increase and it generates more realistic behaviors of agents. First, we show how to use the concept of holon in crowd simulation and how effective it is. For this reason, we use simple rules for holonification. Using real-world data, we model the...
متن کاملAnalysis of the elastic strain energy driving force for grain boundary migration using phase field simulation
We investigate elastic energy-driven grain boundary migration in a strained copper bicrystal using an atomistically informed phase field model. In a bicrystal experiencing a uniform strain, the softer grain has a lower energy density and grows at the expense of the harder grain. In a bicrystal experiencing heterogeneous strain, the softer grain has a higher energy density, yet it still grows. O...
متن کاملMOLECULAR DYNAMICS SIMUATION STUDY OF GRAIN BOUNDARY MOBILITY IN NANOCRYSTALLINE Pd
We present a new methodology for measuring the grain boundary mobility for curved boundaries using moleculardynamics simulation of grain growth in a small, specifically tailored Pd nanocrystalline structure. In the model system, the boundaries move under the forces provided by their curvature and in the presence of the triple junctions. The study suggests that during the gain growth, the transf...
متن کامل