About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
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Mechanical Behavior at the Nanoscale VI
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Presentation Title |
Strain-rate Dependent Deformation Mechanisms in Multilayer Cu/Mo Thin Films |
Author(s) |
Bibhu Prasad Sahu, Amit Misra, George M. Pharr |
On-Site Speaker (Planned) |
Bibhu Prasad Sahu |
Abstract Scope |
Strain-rate sensitivity and rate-dependent hardness, over a range of 10-2 to 102 s-1, of the sputter-deposited 5 nm Cu/ 5 nm Mo, and 100 nm Cu/ 100 nm Mo multilayer films with a total film thickness of 5 μm were measured using nanoindentation. Multilayer films exhibited enhanced hardness but slightly reduced strain-rate sensitivity with decreasing layer thickness from 100 nm to 5 nm. Only the 5 nm Cu/ 5 nm Mo multilayer film exhibited shear band underneath nanoindents and the size of the shear band increased with increasing strain rate. In contrast, the 100 nm Cu/ 100 nm Mo multilayer film exhibited material pile-up around indents and significant nanotwinning within Cu grains. The effect of strain rate and layer thickness on the hardness and strain rate sensitivity of the multilayer thin films is interpreted using a modified confined layer slip (CLS) model. The reduced rate sensitivity at 5 nm as compared to 100 nm is correlated with abundant growth nanotwins in the Cu grains in 100 nm and formation of shear bands in 5 nm multilayers. |
Proceedings Inclusion? |
Planned: |
Keywords |
Thin Films and Interfaces, Characterization, Mechanical Properties |