Microstructure evolution during Hot Forming Quench process for aircraft

This PhD aims at investigating microstructural evolution during HFQ. Samples obtained from PhD1 using lab scale tests with well-controlled thermo-mechanical conditions will be analyzed with quantitative microstructural investigation applying different complementary techniques (hardness measurements, EBSD, TEM, DSC and XRD1). Therefore, the effect of HFQ processing conditions on further microstructure evolution will be established for an 2**** alloys and can be presented as processing-like map.

The activated physical mechanism and their interactions will be accessed through the analysis of microstructure evolution during the HFQ process with several microstructural quantities (grains size and orientation spread, dislocation density and sub-structures, second phase particle size distribution and volume fraction, crystallographic texture…). Those mechanisms will then be modeled for microstructural predictions and coupling with mechanical behavior.

The main challenges rely on the analysis of interaction between precipitation of hardening phases and plasticity which may involve a number of phenomena: heterogeneous nucleation, faster growth and coarsening of precipitates, recovery and dynamic recrystallisation. The experimental plan was carefully established to get insight into mechanisms which control microstructure evolution of 2*** alloys during HFQ.