The microstructures evolutions have been largely investigated by the different partners and numerous data are available for two alloys chosen in the study (AA 3003 and AA3103). These data can be used for the further description of the microstructure for the forming process and are mainly data that allow comparisons between modelling and experiments.
The procedures for the measurements used by the different partner were compared in a Round Robin test. The mechanisms associated with the microstructure evolution were defined for a large part of the thermal cycle (heating and during the temperature holding). The one during the further cooling have to be further investigated for a full knowledge of these mechanisms.
The nature of the phases appearing on heating, the transformations of the intermetallic primary phases were established.
A quantification of the initial microstructure was performed (Amount, size and shape factor distribution of primary precipitates, Chemical composition of precipitates, microsegregation, DAS).
The following evolution were quantified during heating, maintain at temperatures and further cooling:
- Primary precipitates evolution (amount, size, shape factor, number of particles, change in composition and structure).
- Secondary precipitates (size, number of particles, chemical composition).