Martensitic Phase Transitions in Nanocrystalline Materials

Abstract

The martensitic transformation in Fe-Ni alloys (Ni content between 31 wt% and 36 wt%) was studied by means of X-ray diffraction and transmission electron microscopy in nanocrystalline specimens (polycrystals with a crystal size of 4 nm) as well as in a loose powder of 4 nm sized, isolated Fe-Ni crystals with the same chemical compositions as the nanocrystalline materials. The isolated crystals were embedded in pure paraffin. The result obtained indicates that a martensitic transformation does not occur in the nanocrystalline material because the formation of a martensitic nuclei is inhibited due to the small size of the crystals. The inhibition of a martensitic phase transition may be of technological interest for the generation of improved superconducting, ferromagnetic and ferroelectric materials. Keywords: Iron alloys nickel; Martensitic phase transitions; Nucleation; Nanocrystalline materials; Superconducting ferromagnetic ferroelectric materials.

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Document Details

Document Type
Technical Report
Publication Date
May 15, 1989
Accession Number
ADA208804

Entities

People

  • Herbert Gleiter

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alkanes
  • Alloys
  • Chemical Composition
  • Crystal Lattices
  • Crystal Structure
  • Crystals
  • Diffraction
  • Electrons
  • Materials
  • Materials Science
  • Measurement
  • Phase Transformations
  • Polycrystals
  • Transitions
  • United States
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Metallurgy
  • Thin Film Deposition Science.

Technology Areas

  • Microelectronics