Need for high integrity light weight structural castings

Global warming and resource shortage have lead to an urgent demand for reducing the weight of passenger´s vehicles. Since the first introduction of structural Aluminium cast components in the AUDI A8 back in 1994, additional structural parts have been successfully manufactured by vacuum assisted High Pressure Die Casting (HPDC) technology. 

However, it is still an expensive solution as this process technology requires evacuating the air in the entire die cavity and shot system and therefore it is only affordable for upper class cars. Hence, there is a clear need to develop a cheaper vacuum technology in order to make it available to a wider customer base (lower and medium class passenger vehicles).

To face this challenge, IK4-Azterlan is making important investigation efforts on two of the most promising working lines. On one hand, the substitution of high vacuum processes in HPDC by more competitive processes using low cost, portable vacuum systems which allow to reach an intermediate vacuum level. On the other hand new developments are being applied in the optimization of the Low Pressure Permanent Mold Casting (LPPM) process, also aided by vacuum, in order to overcome the actual thickness limits of this process.

In both technologies, the key is not just to apply vacuum, but it comes to a complex and adequate combination of different technologies, metallurgical knowledge and quality controls.

Soundcast technology success factors (www.soundcastproject.eu)

In IK4-AZTERLAN we trust in the democratization of vacuum assisted HPDC technology, therefore we are directly involved in its development coordinating the Soundcast project FP7-SME-315506. The main objectives of this European project are:

- To provide a more competitive technology by using VDS vacuum equipments easy to fit to medium or high range HPDC machines.

- The use of secondary alloys, cheaper and with a lower die soldering tendency compared to the conventional primary AlSi10MnMg alloy.

- The use of latest generation of lubricants and adequate lubrication practices for subsequent heat treatment and welding operations.

- Application of an intelligent control to the whole manufacturing process.

The latest advances of the Soundcast project were recently presented on the 13th edition of the International Foundry Trade GIFA in Düsseldorf, at the Aluminium 2000 Congress in Florence and in the IFHTSE 2015 in Venice. 

The new recycled AlSi10MnMg alloy with high iron content (0.6 wt. % Fe) has high mechanical properties comparable to the corresponding primary alloy. Furthermore, an efficient new laser welding process applicable to these structural components manufactured by low cost technology has been developed in the frame of the project. The advantages of the Soundcast technology will be fully exploited in the final demonstration of the project which will be performed on two real HPDC parts by the end of the present year.