Mechanisms of stacking fault tetrahedra destruction by gliding dislocations in quenched gold

Abstract

The destruction processes of stacking fault tetrahedra (SFTs) induced by gliding dislocations were examined by transmission electron microscopy (TEM) in situ straining experiments for SFTs with edge lengths ranging from 10 to 50 nm. At least four distinct SFT destruction processes were identified: (1) consistent with a Kimura–Maddin model for both screw and 60° dislocations, (2) stress-induced SFT collapse into a triangular Frank loop, (3) partial annihilation leaving an apex portion and (4) complete annihilation. Process (4) was observed at room temperature only for small SFTs (∼10 nm); however, this process was also frequently observed for larger SFTs (∼30 nm) at higher temperature (∼853 K). When this process was induced, the dislocation always cross-slipped, indicating only screw dislocations can induce this process.

Acknowledgements

This research was sponsored by the Office of Fusion Energy Sciences, US Department of Energy, under contract DE-ACO5-00OR22725 with UT-Battelle, LLC. We thank Dr Thak Sang Byun for valuable comments.