|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Phase Transformation Across Multiscale Material Interfaces
||Analysis of the Stability of Interfaces Fabricated Using Solid State Welds
||Niyanth Sridharan, Maxim Gussev, Chad Parish, Juan Carlos Idrobo Tapia, Kurt A Terrani, Sudarsanam Suresh Babu
|On-Site Speaker (Planned)
Components fabricated using ultrasonic additive manufacturing (UAM) suffer from reduced ductility along the z-axis. Recent work has demonstrated the improvement of the z-axis properties after post-processing treatments. However the abnormally high stability of the interfaces during post weld heat treatments and the associated increases in strength are not well understood. We use atomic scale resolution to characterize these interfaces. HRTEM/EELS show local enrichment of oxygen (possibly from the surface oxide) in the grain boundaries near the interfaces. To account for the stability of the grains two hypothesis are proposed and evaluated; viz. highly non equilibrium nano dispersed oxides impeding the grain growth due to grain boundary pinning, or segregation of O resulting from the decomposition of the oxide film during processing.
||Planned: Supplemental Proceedings volume