Effects of composition, thermal ageing and deformation on the microstructure-property relationship in Al-6xxx alloys

The lightweighting of current automotive structures is crucial for improved vehicle energy efficiency, in particular with the move to battery electric vehicles. Improving the mechanical properties beyond that of current commercial Al alloys enables reduction in component weight and a wider range of suitable applications for these alloys. Not only can components fabricated from Al-6xxx (Al-Mg-Si-Cu alloys) offer good lightweight solutions, but the infinite recyclability of these alloys at end of component lifetime ensure sustainability is included in their manufacturing. This high recyclability also means future components can be manufactured from post-consumer scrap with very low inherent CO₂ content.

Recent advances have shown that deformation included as part of the thermal ageing process of these alloys creates an improvement in alloy mechanical properties, beyond the linear combination of the process of cold work and thermal ageing. To understand the underlying mechanisms behind these improvements, the technique of Atom Probe Tomography (APT) has proved to be highly effective, providing chemical quantification of individual atoms within materials, and with full 3D near-atomic scale spatial resolution. 

This new project aims to build on previous work investigating the effect changes in alloy chemistry in particular and thermal ageing history have on the combined mechanical-thermal ageing process. The researcher will be trained to be an independent, expert user of APT in the Oxford group, using this to investigate the mechanisms of precipitate shearing, nucleation and growth that occur during the thermomechanical ageing process. 

It will also be co-supervised by academics based in Brunel University, where Constellium have built up a University Technology Centre. Constellium are a global leading manufacturer of high-quality technically advanced aluminium products and systems. The successful applicant will have the opportunity to work alongside these industrial partners and contribute to Constellium’s strategic R&D aims. This includes a 3-month work placement within Constellium’s international business.

Full funding for this project is currently being put in place, courtesy of Constellium/EPSRC.