Probe the defect generation and propagation mechanisms in flash sintered high temperature ceramics via in situ TEM
Abstract
The proposed research in this project aims to explore the fundamental mechanisms for the formation of these field-induced defects, the interactions between the field-induced defects and the deformation-induced defects and the coupled effects for enhanced mechanical ductility. More specifically, the PI proposes to apply a unique combination of in situ TEM tools on flash sinteredceramics to probe the nature of the field-induced defects (dislocations, stacking faults, and their networks), and their interactions under external stimuli including applied electric bias, heating and stress. Coupled with the newly installed ASTAR tool for grain orientation mapping (a new nanograin orientation mapping tool in TEM), we believe that it is now possible to identify the underlying mechanisms for the enhanced ductility, such as dislocation motion and entanglement, grain boundary rotations, and stacking faults induced serrations.The impacts of the fundamental study are enormous and many-fold: (1) the direct real-time monitoring of the dynamic process of defects formation and motions under filed and temperature is critical for revealing the deformation and densification process of flash sintering; (2) the direct observation of grain boundary rotation in different HTC systems is critical in understanding theoverall flash sintering process and will provide critical parameters for the phase field modeling for the flash sintering events; and (3) the understanding of the field-induced defect generation and interactions during deformation process is critical for future designs of flash sintered ceramics with novel mechanical behaviors, e.g., high hardness, enhanced ductility and facture toughness.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 09, 2020
- Source ID
- N000142012043
Entities
People
- Haiyan Wang
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia