|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Ultrafine Grained Materials IX
||Study of Dynamic Recovery in Nanocrystalline Metals Using In-situ X-ray Diffraction and MD Simulations
||Zhen Sun, Steven Van Petegem, Christian Brandl, Manas Upadhyay, Karsten Durst, Wolfgang Blum, Helena Van Swygenhoven
|On-Site Speaker (Planned)
||Steven Van Petegem
Transient testing has proven to be a suitable tool to gather information on the rate limiting deformation mechanisms that are activated during the deformation path. In this work, we combine stress reduction tests with in situ x-ray diffraction at the Swiss Light Source. The transient response is captured in terms of evolution of strain rate and diffraction peak broadening. The constant flow stress reached during uniaxial deformation of electrodeposited nanocrystalline Ni reflects a quasi-stationary balance between dislocation slip and recovery mechanisms. To gain further knowledge on the interplay between dislocation mechanism and grain boundary recovery mechanisms, molecular dynamics simulations (MD) have been performed. Stress reduction experiments have been simulated followed by creep simulations up to 1.7 ns. The simulations confirm the interpretation of the behavior of the peak broadening during insitu diffraction experiments: after a stress drop strain is produced by grain boundary accommodation mechanisms.