The 9th International Conference on Multiscale Materials Modeling

講演情報

Symposium

I. Multiscale Modeling of Grain Boundary Dynamics, Grain Growth and Polycrystal Plasticity

[SY-I8] Symposium I-8

2018年10月31日(水) 16:00 〜 17:00 Room7

Chair: Srikanth Patala(North Carolina State University, United States of America)

[SY-I8] Polycrystal plasticity with anisotropic grain boundary energy described on the five-dimensional grain boundary space

Nikhil Chandra Admal1, Javier Segurado2,1, Jaime Marian1 (1.University of California Los Angeles, United States of America, 2.IMDEA, Spain)

At high temperatures, grain boundaries are not static entities but can migrate in response to thermo-mechanical forces brought about by temperature, external stresses, and internal microstructure. This gives rise to a wide array of dynamic behavior, including recovery, recrystallization, grain growth, etc.

In this talk, we present a recently developed three-dimensional polycrystal plasticity model driven by a single energy functional that captures both grain boundary (GB) energy and bulk elastic energy in response to plastic deformation. The model represents any arbitrary grain boundary using geometrically necessary dislocations (GNDs), and the GB energy is constructed as a function of the GNDs. Moreover, in contrast to previous phase-field approaches for grain boundary evolution, our model’s energy functional is described on the entire five-dimensional grain boundary space allowing the consideration of both misorientation and inclination in the grain boundary energy.

The model is parameterized using grain boundary energy data from atomistic simulations, after which it is used to simulate the microstructure evolution of polycrystalline samples. The framework is used first to simulate the recrystallization process in a three dimensional polycrystal without external loads. Finally, the deformation of polycrystals under external loads is simulated for a few selected cases.