The study was presented just last month at Aachen Body Engineering Days 2018.

Hydro participated with engineering expertise from three of its business areas: Extruded Solutions, Primary Metal and Rolled Products.

“This is a great example on how our customers and society can profit from Hydro being a completely integrated company with expertise along the whole value chain,” says Pascal Wagner, head of global products for Hydro’s Rolled Products business area.

“This project has given us the ability to promote our broad product range to an important audience. Extrusion alloys, sheet grades and ‘green’ metals are all well appreciated,” says Wagner.

Sustainable urbanization is key

This past May, the United Nations’ Department of Economic and Social Affairs released a report stating that 68 percent of the world population would be living in urban areas by 2050. Further, the UN reported that sustainable urbanization would be key to sustainable development.

With the macro-economic cost of traffic jams in Europe having tripled between 2006 and 2011, in addition to greater space limitations and carbon dioxide emissions in cities, conventional cars are being pushed out of cities. New vehicle and mobility concepts are moving in.

Focused on the L7e micro-car class, the new study by Hydro and fka demonstrates how cars for urban driving can be constructed largely in aluminium. It shows how aluminium can enable cars to achieve the L7e classification and still reach the safety levels typically provided by larger cars.

Light and agile cars in aluminium

The L7e vehicle class describes a small and light, battery-driven micro-car. The requirements for such cars are:

• Under 3.7 meters in length, 1.5 meters wide, and 2.5 meters high
• Lighter than 450 kilograms (excluding the battery system)
• Maximum continuous rated power 15 kW
• Maximum speed of 90 kilometers per hour
• A closed body with no fewer than three opening sides
• Maximum of four non-straddle seats with safety belts

Cars within the L7e class, however, normally do not offer the same passive safety system for passengers as larger models. Consequently, customers have found such vehicles unattractive.

Raising the level of passive safety was one of the targets of the L7e project. “We tested the passive safety performance of our concept L7e micro-car according to Euro NCAP crash test methods – and the vehicle passed every test for normal M1-class cars,” says Nunzio Cuppoletta, who is responsible for the automotive market sector for Hydro’s Extrusion Europe business unit.

Individual mobility in urban areas

Light and efficient micro-cars with electric drivetrains can contribute to ensure individual mobility in urban areas. The potential for aluminium lightweighting in these vehicles is substantial, due to the metal’s low density, good stiffness properties and high level of specific energy absorption.

The concept car’s innovative body structure was built exclusively with aluminium – structural sheet, extrusions and castings. All the extruded solutions were manufactured with 6xxx-series alloys, as well as all but one of the sheet components.

Wagner says that the main challenge with the body structure was to create a deformation space sufficient enough to guarantee the safety of passengers in case of a collision. Again, aluminium –with its high energy-absorption capability – was crucial for the new structure.