THE ROLE OF STRAIN IN THE NUCLEATION OF SOLID STATE TRANSFORMATIONS.

Abstract

The allotropic transformations in iron, cobalt, cerium, and lanthanum were studied with the objective of establishing the factors which are influential in the initiation and propagation of the transformation. From a study of zone-refined iron it was concluded that interstitial solutes are not essential for the martensitic transformation of iron. The FCC-HCP martensitic transformation was studied in whiskers, bulk single crystals and polycrystalline specimens of cobalt. From the measured effect of stress on the transformation it was concluded that the transformation was very defect sensitive and the habit plane was not controlled by a critical resolved shear stress criterion. In cerium, both the FCC-FCC and FCC-HCP transformations were studied in polycrystalline specimens. The FCC-HCP transformation in lanthanum was found to occur isothermally, in contrast to the other allotropic transformations studied in this work. (Author)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1964
Accession Number
AD0609017

Entities

People

  • C. A. Wert
  • C. J. Altstetter
  • J. O. Nelson
  • M. S. Rashid

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Contrast
  • Crystal Structure
  • Crystals
  • Lanthanum
  • Nucleation
  • Polycrystals
  • Shear Stresses
  • Single Crystals
  • Stresses

Readers

  • Agricultural Chemistry/Soil Science
  • Materials Science and Engineering.
  • Metallurgy