Effect of trace Ag on the microstructure and precipitation of an Al-Cu-Mg alloy

This paper investigated the effect of different amounts of Ag addition on the microstructure, properties and precipitation processes of Al-4(.)6Cu-6(.)9Mg(wt-%) alloy using various analytical methods. It was found that Ag addition stimulated new x' and V phases precipitated finely and dispersively in the matrix, as a result of Mg-Ag co-clusters; the volume fraction of precipitates increased with the content of Ag addition. Such precipitation improved the mechanical performance of the Al-Cu-Mg alloy significantly. The mechanism for the formation of new precipitates is also described in this paper.