| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
100 Years and Still Cracking: A Griffith Fracture Symposium
|
| Presentation Title |
Fracture Resistance of Hierarchical Metallic Nanocomposite Thin Films |
| Author(s) |
Amit Misra, Y. Cui, B. K. Derby, N. Li |
| On-Site Speaker (Planned) |
Amit Misra |
| Abstract Scope |
Nanolayered metallic materials exhibit ultra-high strengths as the composition modulation wavelength decreases below approximately 10 nm but fail via shear localization resulting in limited toughness. In a model Cu-Mo system synthesized via co-sputtering at elevated temperatures, a hierarchical morphology of a matrix of phase-separated Cu-Mo with nanoscale ligaments dispersed with sub-micron scale Cu-rich islands containing Mo nano-precipitates was discovered. Fracture experiments conducted via in situ 3-point bend testing of pre-notched microbeams in SEM revealed that the nanoscale hierarchical morphology exhibits superior crack growth resistance as compared multilayer morphology. The toughening mechanisms in hierarchical microstructures involved crack bridging by the Cu-rich layer, crack deflection via shear along the Cu/Mo interface, and multiple cracking. This work demonstrates an approach to increase toughness in high strength nanocomposites through interface micro-structure design. |
| Proceedings Inclusion? |
Planned: |