Dislocation Dynamics and Grain Boundary Evolution

Collaborators: David J. Srolovitz, Mikko Haataja, S.S. Jerry Quek, Zi Chen, Adele Lim

Six interacting dislocation lines
Six interacting dislocation lines. (Image courtesy of Zhaoxuan Wu)

Understanding the role of dislocations and grain boundary evolution in the plastic deformation of materials continues to present an important and interesting challenge for material scientists. We studied both of these microstructural entities using mesoscopic computational models based on the level set method.

In our model, dislocations are represented by the intersection of the zero level sets of two level set functions. An important consequence of this implicit representation of the dislocation line is that topological changes that occur when dislocation lines interact with obstacles and with each other take place automatically without requiring complicated ``surgical procedures.''

To address the computational complexity of modeling dislocation networks and grain boundaries using the level set method, we have implemented the Level Set Method Dislocation Dyanmics (LSMDD) library. This software library is designed to support high-performance, parallel computation and to be modular enough to allow for exploration of novel numerical models and algorithms for simulating dislocation dynamics and interactions.

Working notes

References

  1. Chen, Z., Chu, K. T., Srolovitz, D. J., Rickman, J. M., & Haataja, M. P. (2010). Dislocation Climb-Strengthening in Systems with Immobile Obstacles: a 3D level-let simulation study. Phys. Rev. B, 81(5), 054104. https://doi.org/10.1103/PhysRevB.81.054104 [pdf]
  2. Chu, K. T., & Lim, A. T. (2007). Constructing Dislocation Models of Low-Angle Grain Boundaries. PRISM. [pdf]