The influence of Mg content on the formation and reversion of Guinier-Preston zones in Al-4.5 at % Zn-x Mg alloys

G. Honyek, I. Kovács, J. Lendvai, Ng-Huy-Sinh, T. Ungár, H. Löffler, R. Gerlach

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The influence of Mg concentrations on the dissolution of Guinier-Preston (GP) zones formed at room temperature (RT) and on the formation of more stable phases has been investigated during continuous heating of Al-4.5 at % Zn-xMg alloys. The Mg content was varied from 0.05 to 3 at %. After different aging periods at RT, calorimetric investigations were carried out at heating rates of 40 and 80° C min-1. In the case of alloys with a lower Mg content (x ≤ 0.5 at %) only the dissolution of GP zones could be observed during the heating, whereas in the case of alloys with a higher Mg content the formation of the η′-phase started before the total dissolution of GP zones and at higher temperatures the formation of the η-phase also took place. These phases were identified by transmission electron microscopy. The heat-of-solution of GP zones shows saturation as a function of RT aging time. The time needed for the saturation increased monotonously with increasing Mg content. The reversion of zones was followed by in situ X-ray small angle scattering measurements. The change of the total scattered intensity was measured during continuous heating at a rate of 40° C min-1. These investigations have confirmed the results of the calorimetric measurements which indicate that the total dissolution of zones takes place only in the case of the alloys with a Mg content lower than 0.5 at %. In the case of alloys with a Zn concentration of 4.5 at % studied here, 1 at % Mg is sufficient to initiate the formation of more stable phases during the reversion of zones.

Original languageEnglish
Pages (from-to)2701-2709
Number of pages9
JournalJournal of Materials Science
Volume16
Issue number10
DOIs
Publication statusPublished - Oct 1981

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'The influence of Mg content on the formation and reversion of Guinier-Preston zones in Al-4.5 at % Zn-x Mg alloys'. Together they form a unique fingerprint.

  • Cite this