Quantification of grain boundary precipitation and the influence of quench rate in 6XXX aluminum alloys

The extent of grain boundary precipitation has a strong influence on the ductility, fracture toughness and formability of Al alloys. An experimental method for quantifying the level of grain boundary precipitation is described and applied to the Al alloy AA6111 subjected to a range of quenching rates. A threshold quenching rate can be identified above which the degree of grain boundary precipitate is insensitive to the quenching rate.