Potential of horizontal direct chill cast EN AW 6082 rods as forging stock in the manufacture of light weight suspension components

Abstract

Commercial EN AW 6082 rods cast at less than 50 mm in diameter via horizontal casting appear to be adequate candidate as forging stock for the manufacture of small size automotive suspension components. Cast forging stock relies entirely on the forging deformation to develop the fibering known to be very beneficial for superior dynamic and impact properties. Hence, the forging die design is critical to ensure the sufficient amount and suitable orientation of fibering across the section of the component. Forgings produced from cast stock, submitted to an artificial ageing cycle directly after the forging step offer superior fatigue and impact energy values with respect to their counterparts processed with a solution heat treatment (SHT). The superior fatigue and impact energy values of the former are attributed to the particle characteristics; i.e. the spacing of void forming particles in these forgings is relatively smaller than in forgings processed with a separate SHT. The coalescence of voids at these particles eventually occurs at smaller loads and deteriorates toughness.