3DAP characterization and thermal stability of nano-scale clusters in Al-Mg-Si alloys

Ai Serizawa, Shoichi Hirosawa, Tatsuo Sato

Research output: Chapter in Book/Report/Conference proceedingConference contribution

39 Citations (Scopus)


The formation of nano-scale clusters (nanoclusters) prior to the precipitation of the strengthening β" phase significantly influences the two-step aging behavior of Al-Mg-Si alloys. In this work, two types of nanoclusters are found to be formed at different temperatures. The characterization of these two nanoclusters has been performed from the viewpoints of composition and thermal stability using a three-dimensional atom probe (3DAP) and differential scanning calorimetry (DSC). Mg-Si co-clusters formed at room temperature (RT), Cluster(1), play a deleterious role in the subsequent formation of the β" phase because of the high thermal stability even at the bake-hardening (BH) temperature of 443K. In contrast, the nanoclusters formed by pre-aging at 373K, Cluster(2), are effective in the formation of the refined β", suggesting that Cluster(2) transforms more easily into the β" phase than Cluster(1). The quantitative estimation of the chemical compositions of the two nanoclusters suggests that the Mg/Si ratio is one of the key factors in addition to the internal structures consisting of Si, Mg and probably vacancies. The detailed two-step aging mechanism in Al-Mg-Si alloys is proposed based on the characteristics of the two types of nanoclusters.

Original languageEnglish
Title of host publicationMaterials Science Forum
Number of pages6
EditionPART 1
Publication statusPublished - 2006
Externally publishedYes
Event10th International Conference on Aluminium Alloys, (ICAA-10) - Vancouver
Duration: 2006 Jul 92006 Jul 13

Publication series

NameMaterials Science Forum
NumberPART 1
ISSN (Print)02555476


Other10th International Conference on Aluminium Alloys, (ICAA-10)



  • 3DAP
  • Al-Mg-Si alloy
  • DSC
  • Nanoclusters
  • Up-quenching

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Serizawa, A., Hirosawa, S., & Sato, T. (2006). 3DAP characterization and thermal stability of nano-scale clusters in Al-Mg-Si alloys. In Materials Science Forum (PART 1 ed., Vol. 519-521, pp. 245-250). (Materials Science Forum; Vol. 519-521, No. PART 1).