| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
30 Years of Nanoindentation with the Oliver-Pharr Method and Beyond
|
| Presentation Title |
Optimization of Segregation-engineered Nanocrystalline Al Alloys Using Nanomechanical Testing |
| Author(s) |
Daniel S. Gianola |
| On-Site Speaker (Planned) |
Daniel S. Gianola |
| Abstract Scope |
Modern aluminum alloys have made great strides in ambient temperature performance and are amenable to advanced production routes such as additive manufacturing, but lack elevated temperature robustness where gains in efficiency can be obtained. We demonstrate the intentional design of disorder at interfaces in segregation-engineered ternary nanocrystalline alloys that exhibit exceptional thermal stability and elevated temperature strength. Combinatorial thin film depositions produce libraries from 4 ternary systems, enabling downselection of optimized compositions for bulk processing aided by rapid nanomechanical testing. Experiments point to synergistic co-segregation of alloying additions driving the evolution of amorphous intergranular films separating sub- 10 nm Al-rich grains, which gives rise to emergent thermal stability. We ascribe this intriguing behavior to near-equilibrium interface conditions followed by kinetically sluggish intermetallic precipitation in the confined disordered region. The resulting outstanding mechanical performance at high homologous temperatures lends credence to the efficacy of promoting disorder in alloy design and discovery. |
| Proceedings Inclusion? |
Planned: |