Thixoforming of aluminium alloy for weight saving of a suspension steering knuckle

Abstract

The employment of light alloys aimed at weight saving is becoming a stringent need in the transport industry due to the environmental and social pressure. Fuel consumption and exhaust emissions are in fact strongly dependent on car weight and for such a reason, the automotive indutry is looking at both innovative process technologies which make use of light alloys and new design methodologies.

On such a base, after a brief analysis of the approach to be adopted for meeting the environmental goal, the paper describes the development of a suspension steering knuckle through the application of thixoforming technology of an aluminium alloy. It is described the methodology which was used for material/technology choice and component optimisation. A component weight saving of about 30% was obtained, compared to the previous solution made of cast iron.
Prototypes of the optimised steering knuckles were manufactured by using a thixoforming Bühler machine.
The following metallurgical analysis and bench testing demonstrated the suitability of thixoforming process for the development of aluminium safety parts.