About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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30 Years of Nanoindentation with the Oliver-Pharr Method and Beyond
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Presentation Title |
NOW ON-DEMAND ONLY – Simulations and Experiments of the Strain Rate Sensitivity Measurements Using Conical and Spherical Indentation Creep |
Author(s) |
Yousuf Mohammed, Donald Stone, Abdelmageed A. Elmustafa |
On-Site Speaker (Planned) |
Abdelmageed A. Elmustafa |
Abstract Scope |
The hardness and flow stress strain rate sensitivities, mH, mσ, in indentation creep with conical and spherical tips is examined. mH/mσ extend previous results for cones in terms of a universal curve that describes mH/mσ as a function of H/E*/ϵH for small H/E*/ϵH (fully plastic ≈1.0) to H/E*/ϵH≈2.5 (fully elastic≈0).
For cone, the strain level is determined by the angle β (25.3°,22.5°,19.7°). mH/mσ becomes vanishingly small and the material undergoes full elastic deformation for H⁄E*≈0.23 and 0.18 for β of 23.5° and 19.7° compared to β of 22.5° for which H⁄E*≈0.21.
For spherical indentations, the strain is a function of indent radius/indenter radius ratio (a/R). mH/mσ does not maintain unique relation with( H)⁄E* and varies with the increase in (a/R) ratio. The data clustered into a single curve similar to the one produced for conical indentation and that mH/mσ approaches zero for a normalized (H⁄E* ) ⁄ (a⁄R) of ≈0.4. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, |