“Bulk nanostructured materials” commonly refers to macroscopic dense materials (e.g., metals) with nanoscale grains (e.g., &lt;100 nm).1 In this area, “top-down” processing techniques, such as extensive plastic deformation, are typically employed to reduce the grain sizes of metal. BNMs have novel mechanical properties2-5 based on the interplay of microstructural features such as grain size, grain boundaries and twinning. Bottom-up techniques, such as consolidation of ultrafine particles,1 have also been employed in powder metallurgy for making BNMs, which however, does not have fine control over the above-mentioned microstructural features. Since a diverse array of chemically synthesized, well-defined metal nanocrystals have become available,6-9 we are now much better prepared to rethink bottom-up strategies to assemble them into bulk-sized engineering materials. There has been abundant knowledge of synthesizing metal nanocrystals with well-defined size, shape, surface and even interior structures (e.g., multiple twinning with a single nanoparticle). This can potentially lead to new BNMs with unprecedented microstructures. In addition, the resulting new BNMs could also have a range of other “collective” electronic, optical and thermal properties due to strong coupling of the nanocrystals.
|Effective start/end date||9/1/17 → 12/31/20|
- National Science Foundation (DMR-1747776)