Optimised joining technologies for battery enclosures in plug-in hybrid and fully electric vehicles.

Introduction:
Around 80 million passenger cars were produced worldwide in 2017 and with the high rate of development in China and India, this is likely to exceed 100 million by 2025. Emissions from passenger vehicles represent a significant environmental challenge and to meet legislative requirements, alternative powertrain technologies such as hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs) will rapidly increase in market share. By 2030, the percentage share of the production volume of HEVs and BEVs is predicted to increase from a current level of 13% to 37% and 3% to 25%, respectively. One key, safety-critical, component in battery vehicles is the battery enclosure. The enclosure must resist crash and intrusion and must not leak to safeguard the batteries and passengers.
Outline of the research project:
Large volume automotive manufacturers are focused on aluminium alloy extrusions for battery enclosure as they offer significant lightweighting opportunities and avoid recycling issues associated with carbon-fibre composites. For enclosures to meet performance, dimensional accuracy and cost specifications, it is critical that optimised combinations of alloy types and joining (welding) technologies are established. Manufacture of complex, multipart welded aluminium alloy components is challenging and this project will tackle the critical challenge of upscaling to a full-sized component by using key microstructural indicators to help define the optimum combination of alloy composition, joining technology and joint design.
Project details:
Working closely with our industrial partner Constellium - a leader in high value-added aluminium products and solutions for the global automotive industry - the project will focus on the use of advanced characterisation techniques to collect quantitative microstructural information and establish links to mechanical performance.

The main activities at Loughborough will concentrate on advanced techniques available in the Loughborough Materials Characterisation Centre (LMCC) and elsewhere to perform the following:
Investigate the effect of alloy composition and weld parameters. This will take advantage of a new state-of-the-art plasma-focussed ion beam microscope in the LMCC to perform 3D characterisation of chemical distribution and texture.
Apply high-resolution electron microscopy techniques to study microstructure at the nano-scale in different parts of the weld with varying initial alloy conditions and post-joining treatments.
In collaboration with Professor Michael Moody at the University of Oxford, perform atom probe tomography to investigate the size, type and distribution of the strengthening particles in 3D at the atomic scale.

The proposed project aligns with the Loughborough University Beacons: "High Value Manufacture" and "Transport Technologies" as well as the Transport and Travel research priority in the "Energy Global Challenge". It fits well with the Materials Engineering and the Manufacturing Technologies research areas of the EPSRC "Manufacturing the Future" theme and the Manufacturing Technologies research area of the EPSRC "Energy" theme.