Journal of Materials Research

Articles

Microstructural evolution during the heat treatment of nanocrystalline alloys

A.J. Detora1 and C.A. Schuha1 c1

a1 Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

Abstract

Nanocrystalline alloys often show exceptional thermal stability as a consequence of kinetic and thermodynamic impediments to grain growth. However, evaluating the various contributions to stability requires detailed investigation of the solute distribution, which is challenging within the fine structural-length-scales of nanocrystalline materials. In the present work, we use a variety of techniques to assess changes in the grain size, chemical ordering, grain-boundary segregation, and grain-boundary structure during the heat treatment of Ni–W specimens synthesized over a wide range of grain sizes from 3 to 70 nm. A schematic microstructural evolution map is also developed based on analytical models of the various processes activated during annealing, highlighting the effects of alloying in nanocrystalline materials.

(Received April 11 2007)

(Accepted August 7 2007)

Key Words:

  • Alloy;
  • Annealing;
  • Nanostructure

Correspondence:

c1 Address all correspondence to this author. e-mail: schuh@mit.edu

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