Effect of Trace Addition of Ag on the Precipitation Behavior of Al-Mg-Cu Alloy

Authors

  • Mami Mihara Tokyo Institute of Technology
  • Equo Kobayashi Tokyo Institute of Technology
  • Tatsuo Sato Tokyo Institute of Technology

DOI:

https://doi.org/10.4186/ej.2015.19.3.75

Keywords:

Aluminium-magnesium-cupper alloy, silver addition, age-hardening, microalloying, precipitate, transmission electron microscopy (TEM).

Abstract

Effect of Ag addition on the age-hardening response and precipitate microstructure of the Al-3.0Mg-1.0Cu (wt%) alloy has been investigated by micro Vickers hardness and transmission electron microscopy (TEM). The alloy compositions located in the (α+S+T) phase field of the Al-Mg-Cu phase diagram are known to be effective to harden in two stages separated by a distinct and often prolonged hardness plateau. The first stage of hardening occurs very rapidly (e.g. within 60 s at 443 K) and contributes to increase the hardness as much as 50% of the total age-hardening. Trace addition of Ag changes the age hardening response of the Al-3.0Mg-1.0Cu alloy dramatically. In the Ag-added alloy, the hardness change during the first stage of hardening is larger and the plateau stage is shortened as a result of the fast arrival at the second stage of hardness. The microstructure at the plateau stage of hardening for the Al-3.0Mg-1.0Cu alloy exhibits no clear evidence of any precipitates contributing to the first rapid hardening. On the other hand, lath-shaped S phase was observed at the peak hardness. In the Ag-added alloy, fine distributed precipitates were obtained from the beginning of age-hardening.

Downloads

Download data is not yet available.

Author Biographies

Mami Mihara

Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Tokyo 152-8552, Japan

Equo Kobayashi

Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Tokyo 152-8552, Japan

Tatsuo Sato

Precision and Intelligence Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan

Published

Vol 19 No 3, May 28, 2015

How to Cite

[1]
M. Mihara, E. Kobayashi, and T. Sato, “Effect of Trace Addition of Ag on the Precipitation Behavior of Al-Mg-Cu Alloy”, Eng. J., vol. 19, no. 3, pp. 75-84, May 2015.