Measurement and Interpretation of Isothermal-Martensitic Kinetics

Abstract

A brief survey of experimental work on isothermal martensitic transformations is given. Recent results on quantitative metallography are presented. Models for the isothermal kinetics and the method of evaluating the autocatalytic factor as well as the activation free energy for nucleation are discussed. The linear dependence of the activation energy on the chemical free energy change is found to extrapolate satisfactorily to the low M sub s temperatures exhibited by Fe-Ni alloys. The values obtained by substituting the above empirically-determined parameters into the Kaufman-Cohen nucleation equation indicate that the embryos in Fe-Ni alloys are more potent than those in Fe-Ni-Mn alloys, whereas the interfacial energies are quite similar.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1970
Accession Number
AD0715791

Entities

People

  • Morris B Cohen
  • Vijay Raghavan

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alloys
  • Boundaries
  • Curve Fitting
  • Energy
  • Equations
  • Free Energy
  • Frequency
  • Geometry
  • Grain Size
  • Heat Of Activation
  • Kinetics
  • Materials
  • Materials Science
  • Measurement
  • Metallography
  • Metallurgy
  • Microstructure

Readers

  • Materials Science (Mechanical Engineering).
  • Organic Chemistry
  • Systems Analysis and Design