Aluminium is recognised as having the best cost-to-weight ratio for lightweight components, and also has specific qualities which make it ideal for vehicle assembly such as its recyclability, flexibility, malleability, corrosion resistance and low environmental impact.
Its low density can lead to significant weight savings of up to 50% in a vehicle, while its corrosion resistance makes it suitable for body panels too.
Aluminium has begun to replace steel parts and been progressively incorporated into doors, boots, bonnets and engines. The decreased weight also improves towing, hauling, acceleration and stopping abilities, making the vehicle more efficient.
Graph source: McKinsey, Clearwater International Research
Plastics and polymer composites have been essential to a wide range of safety and performance breakthroughs in vehicles. While typically making up 50% of the volume of a new light vehicle, they still only account for less than 10% of its weight.
Industry experts say carbon fibre-reinforced polymers probably have the most potential to help reduce vehicle weight because of their high strength-to-weight ratios and corrosion resistance. However, the biggest hurdle to their implementation in mainstream vehicle models remains cost.
In the drive for even more weight saving in future vehicles, magnesium will become increasingly important in the next generation of automotive designs. Lightweight magnesium requires far less energy during the die cast production process, and designs can be more elaborate without sacrificing strength. The advantages of magnesium over steel include:
- 75% lighter;
- Can achieve complicated thin-walled net shape casting;
- Components can be consolidated into a single die cast magnesium part which improves rigidity and reduces welding costs;
- Tooling costs are reduced due to consolidation of multiple parts into a single part; and
- Lower working temperatures reduces energy consumption during production and extends die life.