Abstract
The enhanced ductility of cold-rolled (CR) tungsten at room temperature is considered to be related to the activities of dislocations and the associated microstructures. However, the specific mechanism and the exact roles that dislocation activity and microstructure effects play in enhancing ductility in CR tungsten are still subjects of conjecture. In this context, three-dimensional electron backscatter diffraction reveals that a CR tungsten micro-cantilever fractures in a semi-brittle manner within the L-T fracture system. The ductile, blunted region shows high dislocation mobility away from the cracking tip, and its emission pathway is strongly correlated with low-angle grain boundaries. Meanwhile, strain and dislocations blocked at high-angle grain boundaries induces stress cracking and results in brittle intergranular fracture. These ductile and brittle failure modes trigger the crack bridging effect, ultimately leading to controlled crack propagation. This work would provide valuable idea for future investigations into the ductility enhancement of ultra-fine grain W.
Original language | English |
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Article number | 101971 |
Journal | Materialia |
Volume | 33 |
DOIs | |
State | Published - Mar 2024 |
Externally published | Yes |
Funding
This study was supported by the JST , the establishment of university fellowships toward the creation of science technology innovation (Grant Number JPMJFS2102 ) and JSPS KAKENHI (Grant Number 21H01068 ).
Keywords
- Bending test
- Cold-rolled tungsten
- Electron backscattering diffraction (EBSD)
- Fracture
- Grain boundaries