About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
|
Symposium
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Nanostructured Materials in Extreme Environments III
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Presentation Title |
A grain-boundary-relaxed nanocrystalline tungsten alloy with exceptional mechanical property and thermal stability |
Author(s) |
Tongde Shen |
On-Site Speaker (Planned) |
Tongde Shen |
Abstract Scope |
A bulk nanocrystalline (NC) W98.3Y1.0Ti0.7 (WYT) alloy with an average grain size of ~ 9.0 nm was fabricated by high-temperature/high-pressure sintering. The utilized high temperature causes annealing- and segregation-induced structural relaxation of grain boundaries (GBs), resulting in a small GB excess volume of only ~ 0.005 nm, one fifth that of bulk NC tungsten (W). The small grain size and the relaxed GBs make it hard for GBs to emit dislocations, resulting in extremely high hardness of 23.2 GPa, yield strength of 9.4 GPa, and ultimate compressive strength of 13.1 GPa. The hardness of metallic bulk NC WYT is comparable to that of ceramic tungsten carbide. The structure-relaxed GBs lower the thermodynamic driving force for grain growth and result in an extremely high thermal stability - no grain growth occurs in bulk NC WYT annealed at a high temperature of 1500 oC, which is above the recrystallization temperature of W. |
Proceedings Inclusion? |
Planned: |
Keywords |
Nuclear Materials, Mechanical Properties, Other |