The Design of an Experiment to Choose an Aluminum Die Casting Alloy for Energy Absorbing Automotive Components

Targeting a steering wheel as a component requiring energy absorbing characteristics, a development team was set up, consisting of a component supplier, pressure die caster and an aluminum supplier, with the objective of developing a suitable aluminum alloy. The component's desired mechanical properties were outlined and an aluminum alloy system was selected for study. After considering the alloying elements most likely to have an influence on mechanical and casting properties, an experiment was designed to test eight alloy variants and their effect on the as-cast properties of die cast test bars. The bars were tested at three separate laboratories and the results were used to determine the effects of alloying elements and their interactions.

The data confirmed the suitability of a castable aluminum-magnesium alloy, capable of exceeding 205 MPa (30 ksi) Ultimate tensile strength, 105 MPa (15 ksi) 0.2% yield strength and 15% elongation in the as-cast condition. This paper covers the design of experiment, alloy production, casting conditions and interpretation of results leading to the choice of a preferred alloy.