Through-process sensitivity analysis on the effect of process variables on strength in extruded Al–Mg–Si alloys

A concept of through-process modelling for studying the effect of process variables on the strength of extruded Al–Mg–Si alloys is presented. Five models are integrated to model casting, homogenisation, extrusion and ageing of the alloys. It is demonstrated that through-process modelling can be utilised to study isolated effects from variations in processing parameters along the value chain on the strength in the end product, which is usually difficult to obtain from experiments. In the present work it has been focused on strength after artificial ageing and the most critical parameters to follow were therefore the Mg and Si and whether these elements appear in solid solution or present in constituent phases. The as-cast and homogenised structures were predicted reasonably well by the models, and it was found that the casting parameters have a significant influence on the density of constituent particles. Chemical composition and cooling rate from extrusion temperature are the variables with the most prominent effect on the yield stress of extruded and aged sections.