A comparative study of precipitate composition and volume fraction in an Al–Zn–Mg alloy using tomographic atom probe and small-angle X-ray scattering

A. Deschamps, A. Bigot, F. Livet, P. Auger, Y. Bréchet

Research output: Contribution to journalArticleResearchpeer-review

74 Citations (Scopus)

Abstract

The composition and volume fraction of precipitates in an Al–Zn–Mg alloy are investigated by tomographic atom probe (TAP), small-angle X-ray scattering (SAXS) and transmission electron microscopy. Three states of ageing are characterized in detail: slightly underaged, containing mostly the metastable η′ phase; slightly overaged, containing η′ and the stable η phase; overaged, containing only η. The different methods are in full agreement about the last state, with a composition of η close to the bulk composition MgZn2, and a volume fraction of 4.5%. The TAP and SAXS results obtained for microstructures with smaller precipitates show some discrepancy. Notably, the TAP predicts a higher aluminium concentration in the precipitates as well as a higher volume fraction. The artefacts of the two techniques are reviewed in detail and a critical analysis of the results is carried out.

Original languageEnglish
Pages (from-to)2391-2414
Number of pages24
JournalPhilosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
Volume81
Issue number10
DOIs
Publication statusPublished - Oct 2001
Externally publishedYes

Cite this