|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Deformation and Transitions at Interfaces
||Atomistic Simulations of Transient Testing in Nanocrystalline Al
||Maxime Antoine Dupraz, Zhen Sun, Christian Brandl, Helena Van Swygenhoven
|On-Site Speaker (Planned)
||Maxime Antoine Dupraz
To get deeper insight in the interplay between dislocation slip and GB accommodation and to accompany insitu Xray experimental observations during transient testing of nc Ni[Acta Mat 91(2015)91], transient tests have been carried out using molecular dynamics. After deforming the sample with 108 /s, stress drops are carried out and the sample is allowed to creep up to 2.3ns at much lower strain rates (~ 106 /s). Important changes in the grain boundary structure occur via mechanisms such as GB dislocation climb and GB migration. After structural changes new dislocations are emitted and this at much lower applied stresses. Besides confirming the interpretation of the experimental in situ tests, our simulations at low strain rates reveal deformation mechanisms that have not been observed during constant strain simulations at 108 /s, such as dislocation-dislocation interaction mechanisms leaving point defects in grain interior and forwards and backwards motion of grain boundaries.