The effect of natural ageing on the evolution of yield strength during artificial ageing for Al-Mg-Si-Cu alloys

Tensile tests have been conducted at 77 and 293 K in order to examine the effect of natural ageing on the subsequent artificial ageing behaviour of the industrial alloy AA6111. The evolution of the yield stress as a function of ageing time at 180 °C was measured for samples with no natural ageing time and a prolonged period of natural ageing (i.e. T4 material). The nature of the obstacles was characterized in terms of the yield stress …