Journal of Materials Science

, Volume 48, Issue 5, pp 2251–2257

An in situ experimental study of grain growth in a nanocrystalline Fe91Ni8Zr1 alloy

  • Hasan Kotan
  • Kris A. Darling
  • Mostafa Saber
  • Ronald O. Scattergood
  • Carl C. Koch
Article

DOI: 10.1007/s10853-012-7002-1

Cite this article as:
Kotan, H., Darling, K.A., Saber, M. et al. J Mater Sci (2013) 48: 2251. doi:10.1007/s10853-012-7002-1

Abstract

Grain growth and microstructural evolution of thermally stabilized Fe91Ni8Zr1 were investigated by in situ and ex situ studies. Our investigations suggest that the microstructural evolution is fairly slow and the microstructure shows stabilization up to about 700 °C. Above this temperature, a certain fraction of grains grow abnormally into the nanocrystalline matrix, resulting in a bimodal microstructure and causing the complete loss of thermal stability. The reason for abnormal grain growth and the loss of thermal stability is identified as the appearance of the fcc γ-phase and consequent reduction in the total area of grain boundaries and the overall stored energy.

List of symbols

M

Grain boundary mobility

Q

Activation energy

ν

Velocity of grain boundary

D

Grain diameter

h

Specimen thickness

δD

Incremental growth

δG

Change in volume free energy

δГs

Change in surface energy

δГi/gb

Change in the interphase energy-grain boundary energy

As

Free surface area

Ai

Grain interface area

V

Volume of grains

g

Bulk free energy per volume

Гs

Surface energy per area

Гi

α-to-γ interface energy per area

Гgb

Grain boundary energy per area

P

Pressure acting on the grain interfaces

\( \tilde{D} \)

Diffusivity

Do

Frequency factor

r

Diffusion distance

t

Annealing time

T

Annealing temperature

R

Gas constant

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Hasan Kotan
    • 1
  • Kris A. Darling
    • 2
  • Mostafa Saber
    • 1
  • Ronald O. Scattergood
    • 1
  • Carl C. Koch
    • 1
  1. 1.Department of Materials Science and EngineeringNC State UniversityRaleighUSA
  2. 2.U.S. Army Research Laboratory, Weapons and Materials Research Directorate, RDRL-WMM-F, Aberdeen Proving GroundAberdeenUSA