Active slip systems in bcc iron during nanoindentation: A molecular dynamics study

Molecular dynamics (MD) simulations of nanoindentation of alpha-iron (α-Fe) have shown that all previously observed slip plane families i.e. {1 1 0}, {1 1 2} and {1 2 3} were active in the system. The slip plane families, {1 1 0} and {1 2 3}, were more are less equally active whereas {1 1 2} family was the least active. A small fraction of dislocation density was observed on {1 0 0} slip planes arising due to the formation of a 〈1 0 0〉 junctions because of the interaction of a/2 〈1 1 1〉 family of dislocations. It was also shown that the line character of dislocations varied uniformly from edge to screw character without any biasing towards a single character of dislocation at temperatures less than 300 K. These results were found to be consistent even with changing the size of domains, shape of the indenter and rate of loading. Present study has shown that for the prediction of deformation behaviour in α-Fe dislocation activities on {1 2 3} slip planes should also be considered along with the activities of {1 1 0} and {1 1 2} slip planes.