|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Multiscale Architectured Materials (MAM II): Tailoring Mechanical Incompatibility for Superior Properties
||Simultaneous High Strength and Ductility in Nickel Induced by Nanodomains with Size Effects
||Fuping Yuan, Xiaolei Wu, Evan Ma
|On-Site Speaker (Planned)
A defect engineering strategy on the nanoscale is architected to obtain nanocrystal strength with coarse-grain ductility. Spread-out domains (average 7 nm in diameter) were produced in Nickel during electrodeposition, occupying only ~2.4% of the total volume. The resulting Ni achieves a yield strength approaching 1.3 GPa, and a uniform elongation as large as ~30%. Electron microscopy observations and molecular dynamics (MD) simulations demonstrate that the nanodomains effectively block dislocations, akin to the role of precipitates for Orowan hardening. Moreover, the abundant domain boundaries provide dislocation sources and trapping sites of running dislocations for dislocation multiplication, and the ample space in the grain interior allows dislocation storage. A pronounced strain-hardening rate is therefore sustained to enable large uniform elongation. The pinning strength was also found to be closely related to the domain boundary type, the domain size and spacing. The present results should provide insights in metals for enhanced mechanical properties.