Plasticity in Nanomaterials

Abstract

There have been many predictions of the reinforcing effects of carbon nanotubes in various composite matrices but large improvements in properties have not yet been convincingly demonstrated. In the present study, we have successfully realized this possibility in reinforcing nanocrystalline alumina. Fully dense single-wall carbon nanotubes (SWCN)/Al2O3 nanocomposites with nanocrystalline alumina matrix have been fabricated at sintering temperatures as low as 1150 deg. C by spark-plasma-sintering (SPS). A fracture toughness of 9.7 MPam(exp 1/2), nearly three times that of pure nanocrystalline alumina, has been achieved in the 10 vol.% SWCN/Al2O3 composite. Moreover, high-strain-rate superplasticity has been achieved in Al2O3/ZrO2/MgAl2O4 nanocomposite with truly nanocrystalline grain size of 100 nm. Compression superplastic tests were conducted in the temperature range of 1300-1450 deg. C at strain rates 10(exp -3) - 10(exp -1) /s . The results generated a stress exponent of approx. 2 and an activation energy of approx. 620 kJ/mol.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2003
Accession Number
ADP014242

Entities

People

  • Amiya K. Mukherjee
  • Guo-dong Zhan
  • Joshua D. Kuntz
  • Julin Wan

Organizations

  • University of California, Davis

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Carbon Nanotubes
  • Electron Microscopy
  • Fullerenes
  • Grain Size
  • Hardness
  • Heat Of Activation
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Mechanical Working
  • Microscopy
  • Modulus Of Elasticity
  • Nanocomposites
  • Nanomaterials
  • Nanotechnology
  • Particles

Fields of Study

  • Materials science

Readers

  • Nanocomposite Materials Science
  • Powder metallurgy of Titanium alloys.