Aerospace aluminium alloy evolution

The relationship between aerospace aluminum alloy composition and damage evolution during thermo-mechanical processing

From the industrial point of view, aluminum alloys are widely used in aerospace, aeronautics and packaging. Nowadays, products with enhanced properties such as lightness, temperature sustainability, thermal conductivity are needed. Furthermore, the environmental and economical current constraints as well as the recycling requirements prohibit the use of rare or critical elements for the development of new alloys.

In this context, the optimization of the elaboration processes with existing materials is crucial. In the case of thick aluminum plates for aeronautic, elaboration consists in: (i) casting, which generates numerous defects such as phase segregation and porosities, (ii) homogenization, (iii) hot rolling to reduce the thickness of the product to its final dimensions and to close the pores and (iv) subsequent heat-treatments to achieve the desired mechanical properties. During those processing steps, damage evolution depends strongly on the interaction between the microstructure (grain size, intermetallics, porosity), the entrapped hydrogen and the thermo-mechanical loading but is far from being clearly understood.

Indeed, nowadays, rolling scheme selection is mainly empirical or based on simple models, which limits the development of new products and the optimization of the processes. In this context, the project aims, thanks to a multi-scale study coupling high resolution ultrasound technique, neutron tomography and in situ X-ray nanotomography, to determine the relationships between aerospace aluminum alloy composition and damage evolution (pores) during thermo-mechanical processing.
____________________________________________________________________
PROJECT PARTNERS:

                                    CNRS