A Microsegregation Parameter Study of Precipitation in Al-Zn-Mg Alloys.

Abstract

Electron probe microanalysis was used to obtain a statistical microsegregation parameter which describes solute redistribution during the precipitation process in Al-Zn-Mg alloys. Precipitate nucleation and solute diffusion, which depend on the concentration and mobility of vacancies, determine the extent to which redistribution occurs throughout the heat treatment. Solution heat treatment temperature, quench rate, aging temperature and grain size were varied, and the effect of these variations on the distribution of precipitation was measured in terms of the microsegregation parameter. Microsegregation in the initial stages of aging is characterized by apparently independent redistribution of Mg and Zn. This effect may reflect the different solute-vacancy binding energies for these solute elements of Al. As aging proceeds, the alloys exhibit parallel redistribution of Mg and Zn indicating the development of solute partitioning as part of the precipitation process.

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1975
Accession Number
ADA019048

Entities

People

  • Adolf E. Wirsing
  • Gary Judd

Organizations

  • Rensselaer Polytechnic Institute

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Chemical Reactions
  • Diffusion
  • Electron Probes
  • Electrons
  • Grain Size
  • Heat Treatment
  • Microanalysis
  • Mobility
  • Nucleation
  • Precipitates
  • Precipitation
  • Probes
  • Solution Heat Treatment

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Microelectronics