The Effect of Ag-Addition on Precipitation Sequence in Al-1.0mass%Mg₂Si-Excess 0.4mass%Si Alloy

Abstract:

It is well known that Ag additional Al-1.0mass%Mg2Si-excess0.4mass%Si alloy (ex. Si-Ag alloy) has higher hardness and elongation than those of Al-1.0mass%Mg2Si-excess 0.4mass%Si alloy (ex. Si alloy). However, precipitation sequence of ex. Si-Ag alloy is not clear yet. In this work, precipitation sequence of ex. Si-Ag alloy has been investigated using high resolution transmission electron microscopy and X-ray energy dispersive spectroscopy. Precipitates were classified into several kinds by HRTEM images and SAED patterns, and relative frequencies of precipitates were also investigated. Its precipitation sequence was compared with that of ex. Si alloy. Type-A, Type-B and Type-C precipitates as special metastable phase in excess Si type Al-Mg-Si alloy, has been observed in ex. Si-Ag alloy, but β’ phase increased and Type-A and Type-B precipitate decreased in this study. Type-A precipitate was found at only grain boundary.

• Periodical: Materials Science Forum (Volumes 561-565)
• Pages: 239-242
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.561-565.239
• Online since: October 2007
• Authors: Kenji Niwa, Kenji Matsuda, Junya Nakamura, Tatsuo Sato, Susumu Ikeno
• Keywords: Ag Addition, Aging, Al-Mg-Si Alloy, Precipitation Sequence, TEM

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