New research to increase car safety

Making cars lighter, safer and cheaper is one of the automotive industry's biggest challenges. Now, a research project at Jönköping University shows that it is possible to predict during the design phase exactly where a cast aluminium part is at risk of breaking– and thus avoid it altogether.

“By simulating how the molten metal flows, you can see how much stress a component will be able to withstand in reality,” says Jakob Olofsson, Head of Department and Associate Professor in Materials and Manufacturing at the School of Engineering in Jönköping.

Through advanced simulations of how molten aluminium behaves in the mould, researchers can now predict the strength of a component before it is even manufactured. This means that designers can optimize both material consumption and safety, leading to lighter designs, fewer defects and significantly lower manufacturing costs.

Oxide films – the real cause of weak points

The industry has long assumed that pores and the microstructure of the metal were what created weak points. Instead, the project shows that thin oxide films, created when the melt moves too quickly and breaks up, pose the greatest risk of cast parts breaking.

This insight gives the industry new opportunities to design away problems at an early stage, which means that components in cars, for example, can be both lighter and stronger without costing more.

During the project, advanced simulations were compared with physical tests. The results show how the thin oxide films, which are invisible to the naked eye, determine where the cast part will later break.

“We have shown that it is not the pores that dominate, but the oxides that form if the melt becomes turbulent. This changes how the industry needs to think when designing and manufacturing aluminium components,” says Jakob Olofsson.

For the automotive industry, where every kilogram counts and every safety detail matters, this is a major step forward. Better simulations mean increasingly reliable strength calculations, and thus better predictions of how the car and its structures will deform in a collision.

Design and manufacturing must be optimized together

A crucial conclusion is that it is no longer possible to design a component without simultaneously simulating its manufacture.

“You can't just draw a shape and assume that the material will be the same everywhere. The metal must flow smoothly and in a controlled manner to avoid turbulence and oxide formation,” says Jakob Olofsson.

When digital design and casting simulation are combined, companies can minimise defects, use less material, reduce costs and at the same time produce stronger and more predictable components.

This is precisely why technology is now being promoted by the automotive industry.

“At the press conference for the new EX60, Volvo's CEO described how this type of technology makes the car safer, lighter and cheaper. This is exactly the direction the entire industry is heading in,” says Jakob Olofsson.