Strain Rate Dependence of Stabilized, Nanocrystalline Cu Alloy

S. A. Turnage, M. Rajagopalan, K. A. Darling, C. Kale, B. C. Hornbuckle, C. L. Williams, K. N. Solanki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The effect of mechanical loading, particularly at dynamic strain rates, on nanocrystalline (NC) materials has eluded researchers owing to the inherent instability of the NC structure. However, a recently developed NC Cu-10 at.%Ta alloy has exhibited an ability to maintain a NC structure at temperatures up to 873 K. Here, NC Cu-10 at.%Ta is tested under compressive strain rates ranging from 10−3 s−1 up to 105 s−1 and at temperatures from 298 K up to 1073 K. Typical materials show a sharp increase in flow stress occurring around 103 s−1 as deformation mechanisms shift away from thermal activation mechanisms; however, at 298 K, NC Cu-10 at.%Ta observes only a limited increase in flow stress indicating that typical thermally activated mechanisms still apply up to strain rates of 105 s−1. Post deformation analyses indicate a shift from nucleation of full dislocations to increased nucleation of partial dislocations at 298 K. However, as temperature increases, thermal activation mechanisms give way to viscous effects and the high density of nucleated full dislocations leads to a dramatic increase in flow stress.

Original languageEnglish (US)
Title of host publicationDynamic Behavior of Materials, Volume 1 - Proceedings of the 2019 Annual Conference on Experimental and Applied Mechanics
EditorsLeslie E. Lamberson
PublisherSpringer
Pages63-67
Number of pages5
ISBN (Print)9783030300203
DOIs
StatePublished - Jan 1 2020
EventSEM Annual Conference and Exposition on Experimental and Applied Mechanics, 2019 - Reno, United States
Duration: Jun 3 2019Jun 6 2019

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652

Conference

ConferenceSEM Annual Conference and Exposition on Experimental and Applied Mechanics, 2019
Country/TerritoryUnited States
CityReno
Period6/3/196/6/19

Keywords

  • Dynamic behavior
  • Flow stress upturn
  • Nanocrystalline
  • Stabilized
  • Strain rate

ASJC Scopus subject areas

  • General Engineering
  • Computational Mechanics
  • Mechanical Engineering

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