Accession Number:

AD1100988

Title:

Topic 10.3- Tailoring Grain Boundary Chemistry for Failure Resistant Nanostructured Metals

Descriptive Note:

Technical Report,15 Sep 2012,14 Sep 2015

Corporate Author:

University of California - Irvine Irvine United States

Personal Author(s):

Report Date:

2017-01-31

Pagination or Media Count:

12.0

Abstract:

This final report summarizes three years of research on the usage of grain boundary structure as a material variable able to control thetoughness and ductility of nanostructured metals. Experiments on nanocrystalline Ni-W alloys were used to isolate the importance ofinterfacial disorder on failure, showing that additional disorder is welcome if trying to create tough materials. A strategy for amplifying thiseffect through the planned inclusion of amorphous grain boundary complexions was then developed, with Cu-Zr used as a model system.We have created a materials processing route capable of producing nanostructured metal powders with amorphous intergranular films.These powders demonstrate a concurrent increase in both ductility and strength over pure nanostructured Cu, proving that these two materialproperties are not mutually exclusive and going against a traditional materials design paradigm. Atomistic computer simulations were usedthroughout the project to provide mechanistic understanding and to guide alloy selection efforts. In addition to excellent mechanicalproperties, our alloys demonstrated very high thermal stability and are promising candidates for future work on bulk nanostructuredmaterials.

Subject Categories:

  • Properties of Metals and Alloys
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE