[P2-71] An attempt to connect migration of grain boundaries to their atomic
structures with help of Molecular Dynamics
Grain Boundary (GB) migration is at the origin of microstructure evolutions in a large variety of crystalline materials. One of the many challenges to fully understand GB motion has to do with the GB vast panel of atomic configurations and existence of several motive forces or impacting parameters. In this context, atomistic simulations have proven to be particularly useful since GB migration can be investigated under well defined conditions, and large scale systematic investigations are now possible (i.g. [1]).
In this work we report a Molecular Dynamics investigation of the migration of a large panel of CSL GB in fcc Ni. In order to construct lesser known GB with mixed tilt+twist or asymmetric character, we orient and constrain the simulation domain to the CSL lattice defined by the two crystal orientations, in a fashion very similar to the approach proposed in [2]. GB motion may be initiated by a synthetic driving force as defined in [3]. As a result, very different temperature behaviour are observed ranging from athermal, to thermally activated and non monotonous thermal behaviour. Different behaviours are sometimes observed for very similar GBs, confirming the important of the GB atomic structure over the macroscopic geometrical parameters describing GB.
In an attempt to rationalise these results we developed an automated post-processing of the atomic configurations into a discrete modelling of GB in terms of intrinsic dislocations and disconnections when present. This analysing tool is applied to a dozen of simple GB and a correlation is made when possible between elementary migration mechanisms -atomic shuffling or disconnection motion- and discrete structure of GB.
[1] DL Olmsted, EA Holm, SM Foiles, Acta Mater. 57, 3704 (2009).
[2] AD Banadaki, S Patala. J. Appl. Cryst. 48, 585 (2015).
[3] K.G.F. Janssens, D. Olmsted, E.A. Holm, S.M. Foiles, S.J. Plimpton, P.M. Derlet, Nat. Mater. 5, 124 (2006).
In this work we report a Molecular Dynamics investigation of the migration of a large panel of CSL GB in fcc Ni. In order to construct lesser known GB with mixed tilt+twist or asymmetric character, we orient and constrain the simulation domain to the CSL lattice defined by the two crystal orientations, in a fashion very similar to the approach proposed in [2]. GB motion may be initiated by a synthetic driving force as defined in [3]. As a result, very different temperature behaviour are observed ranging from athermal, to thermally activated and non monotonous thermal behaviour. Different behaviours are sometimes observed for very similar GBs, confirming the important of the GB atomic structure over the macroscopic geometrical parameters describing GB.
In an attempt to rationalise these results we developed an automated post-processing of the atomic configurations into a discrete modelling of GB in terms of intrinsic dislocations and disconnections when present. This analysing tool is applied to a dozen of simple GB and a correlation is made when possible between elementary migration mechanisms -atomic shuffling or disconnection motion- and discrete structure of GB.
[1] DL Olmsted, EA Holm, SM Foiles, Acta Mater. 57, 3704 (2009).
[2] AD Banadaki, S Patala. J. Appl. Cryst. 48, 585 (2015).
[3] K.G.F. Janssens, D. Olmsted, E.A. Holm, S.M. Foiles, S.J. Plimpton, P.M. Derlet, Nat. Mater. 5, 124 (2006).