Vacancy behavior during aging at 50 and 100°C in AlMgSi alloys with excess Si studied by positron annihilation spectroscopy

Koji Inoue, Ken Takata, Koji Ichitani, Yasuharu Shirai

Research output: Contribution to journalArticle

Abstract

We have investigated the aging behavior of quenched-in vacancies in excess Si type AlMgSi-alloys by coincidence Doppler broadening of positron annihilation radiation and positron lifetime spectroscopy. The chemical composition around the quenched-in vacancies is initially rich in Si. For aging at both 50°C and 100°C, the Mg/Si composition ratio around the vacancies increases with aging time. The final Mg/Si composition ratio around the vacancies was found to be almost the same for aging at both 50 and 100°C. The difference of the aging time dependence of the chemical composition around the vacancies at 50 and 100°C was observed in the initial stage, i.e., the vacancy-Si-rich solute complexes was formed at 50°C, while the formation of the vacancy-Si-rich solute complexes was avoided at 100°C. Therefore, the avoidance of the formation of the vacancy-Si-rich solute complexes by pre-aging around 100°C before storage at room temperature may be a key to avoid negative effect of artificial aging in AlMgSi alloys.

Original languageEnglish
Pages (from-to)2255-2259
Number of pages5
JournalMaterials Transactions
Volume60
Issue number11
DOIs
Publication statusPublished - 2019 Jan 1

Keywords

  • Aluminum alloys
  • Positron annihilation
  • Vacancies

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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