skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Strengthening Nanotwinned Metals beyond the Hall-Petch Limit

Abstract

A research partnership program was conducted to study the roles of trace element segregation as a fundamentally new mechanism of grain-boundary and twin-boundary strengthening in nanocrystalline-nanotwinned face-centered-cubic silver metals. The goals were to create new metals that break the decades-old theoretical Hall-Petch strength limit, and to study a new class of super-strong conducting materials. This program combined synergistic experimental and computational studies at the atomic scale, using a wide range of resources and scientific expertise at the University of Vermont, Ames Laboratory and Lawrence Livermore National Laboratory. This research led to a discovery that annealing of nanotwinned silver with trace concentrations of Cu solute atoms (<1.0 wt.%) results in grain sizes and twin spacings well below those previously obtained for silver. These new materials, termed as nanocrystalline-nanotwinned silver, showed a record hardness 42% higher than the Hall-Petch limit in pure nanotwinned silver or stronger metals like copper, with excellent retention of electrical conductivity and microstructure stability at elevated temperature. This research used large-scale hybrid Monte-Carlo/molecular-dynamics atomistic simulations and ab-initio calculations to predict new impurity-segregation behaviors and fundamentally new plastic deformation mechanisms in nanocrystalline-nanotwinned silver metals. A new interatomic potential for atomistic simulation of segregation of Ni impurity in Ag grain-boundariesmore » and plasticity of Ag-Ni alloys was developed.« less

Authors:
ORCiD logo [1]
  1. The University of Vermont
Publication Date:
Research Org.:
The University of Vermont
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1574142
Report Number(s):
DOE-UVM-0016270
8026563837
DOE Contract Number:  
SC0016270
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Sansoz, Frederic. Strengthening Nanotwinned Metals beyond the Hall-Petch Limit. United States: N. p., 2019. Web. doi:10.2172/1574142.
Sansoz, Frederic. Strengthening Nanotwinned Metals beyond the Hall-Petch Limit. United States. https://doi.org/10.2172/1574142
Sansoz, Frederic. Thu . "Strengthening Nanotwinned Metals beyond the Hall-Petch Limit". United States. https://doi.org/10.2172/1574142. https://www.osti.gov/servlets/purl/1574142.
@article{osti_1574142,
title = {Strengthening Nanotwinned Metals beyond the Hall-Petch Limit},
author = {Sansoz, Frederic},
abstractNote = {A research partnership program was conducted to study the roles of trace element segregation as a fundamentally new mechanism of grain-boundary and twin-boundary strengthening in nanocrystalline-nanotwinned face-centered-cubic silver metals. The goals were to create new metals that break the decades-old theoretical Hall-Petch strength limit, and to study a new class of super-strong conducting materials. This program combined synergistic experimental and computational studies at the atomic scale, using a wide range of resources and scientific expertise at the University of Vermont, Ames Laboratory and Lawrence Livermore National Laboratory. This research led to a discovery that annealing of nanotwinned silver with trace concentrations of Cu solute atoms (<1.0 wt.%) results in grain sizes and twin spacings well below those previously obtained for silver. These new materials, termed as nanocrystalline-nanotwinned silver, showed a record hardness 42% higher than the Hall-Petch limit in pure nanotwinned silver or stronger metals like copper, with excellent retention of electrical conductivity and microstructure stability at elevated temperature. This research used large-scale hybrid Monte-Carlo/molecular-dynamics atomistic simulations and ab-initio calculations to predict new impurity-segregation behaviors and fundamentally new plastic deformation mechanisms in nanocrystalline-nanotwinned silver metals. A new interatomic potential for atomistic simulation of segregation of Ni impurity in Ag grain-boundaries and plasticity of Ag-Ni alloys was developed.},
doi = {10.2172/1574142},
url = {https://www.osti.gov/biblio/1574142}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {11}
}