Normally when you think of reduced weight and parts count, plastics injection molding comes to mind. But those two goals are achieved with an innovative process called Alcoa Vacuum Die Casting (AVDC), which uses large dies to create durable door assemblies for cars. The inner door panel for the Nissan GT-R is larger than half a square meter, but with a thickness less than 3 mm and a weight of just 5.5 kg per door. That’s a 35 percent reduction compared to conventional designs.
Reinforcing ribs can be added to boost strength, and engineers can also design specific elements, allowing parts reduction. The process uses a special alloy C446, which provides strength and is dimensionally stable. The alloy C446 shows comparable properties to AlSi9Mg without expensive heat treatment.
After closing the die, air is evacuated through the die, and molten metal is then pulled in by low pressure. The formed part is nearly pore free. The castings produced by Alcoa in Soest, Germany have an average strength of 240 Mpa and the average elongation is 15 percent.
The following vehicles use parts made with the process:
- Porsche 911 Turbo (door)
- Porsche 911/Boxter new (body component)
- Nissan GT-R (door, body component)
- Audi A8 (body component)
- Audi R8 Spider (body component)
- Jaguar XJ (body component)
- Jaguar XK (body component)
- Ferrari - all (body component)
- Ferrari F142 (door)
- Karmann, Bentley Continental GTC (roof structure component)
The photo shows an AVDC manufacturing cell at Alcoa’s plant in Soest, Germany.