About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Ultrafine-grained and Heterostructured Materials (UFGH XII)
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Presentation Title |
High Load Sliding, Deformation Microstructures, Strength, and Hardening for Gradient Bulk Nanostructures |
Author(s) |
Darcy Anne Hughes |
On-Site Speaker (Planned) |
Darcy Anne Hughes |
Abstract Scope |
Plowing of wedge shaped micro asperities under large sliding loads, from 0.4 to 3.7 of the yield stress at 293 or 77 K, is utilized to induce extremely high hardness 1.7 to 2.8 GPa and strain levels in the subsurface regions of Cu. A steep gradient in the size scale with increasing depth of the deformation microstructures is measured with transmission electron microscopy including an unprecedented size of 5 nm and high dislocation density near the surface. Subsurface stress estimates use the measured structural parameters in a linear addition of the Hall-Petch formulation for the inverse spacing of geometrically necessary boundaries, 1/DavGNB, plus Taylor dislocation hardening, ρav . A further unification of these parameters is made since the density ρav is directly proportional to 1/DavGNB. Quantitative comparisons and energy balances between the friction and deformation energies corroborate the high hardness and strain levels that may be applied to hard components. |
Proceedings Inclusion? |
Planned: |
Keywords |
Nanotechnology, Mechanical Properties, Characterization |