In situ monitoring of artificial aging and solution heat treatment of a commercial Al–Mg–Si alloy with a high intensity positron beam

Laura Resch*, Thomas Gigl, Gregor Klinser, Christoph Hugenschmidt, Wolfgang Sprengel, Roland Würschum

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

Microstructural changes of a commercial Al–Mg–Si alloy were studied during artificial aging by in situ Doppler broadening spectroscopy using a high-intensity positron beam. The in situ positron annihilation characteristics at high temperatures differ considerably from the conventionally applied ex situ measurements at low temperatures. Therefore, a more comprehensive view of precipitation processes in Al–Mg–Si alloys is obtained. Further, in situ positron–electron annihilation techniques allow for an investigation of aging processes with increased sensitivity. For the artificial aging temperatures of 180 °C and 210 °C pronounced variations of the Doppler broadening S-parameter reveal (i) the evolution of clusters into larger precipitates and (ii) the time of the formation of β" precipitates and the role of vacancies in connection to this. Towards higher aging times, the transformation from coherent β" to semi-coherent β' precipitates could be verified. Additional insights are gained by in situ measurements of the S-parameter during the solution heat treatment of the previously overaged sample. Here, the S-parameter reveals both the dissolution of precipitates starting from temperatures of 364 °C and the thermal generation of vacancies.
Original languageEnglish
Article number085705
JournalJournal of Physics Condensed Matter
Volume32
Issue number8
DOIs
Publication statusPublished - 1 Jan 2020

Keywords

  • Al alloys
  • positron beam
  • positron-electron annihilation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Fingerprint Dive into the research topics of '<i>In situ</i> monitoring of artificial aging and solution heat treatment of a commercial Al–Mg–Si alloy with a high intensity positron beam'. Together they form a unique fingerprint.

Cite this