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A pilot production program was initiated to evaluate the suitability of recycled AZ91D magnesium alloy ingot in a production steering column component. Class I A291D magnesium alloy scrap was remelted and refined using an argon flotation technique. The non-metallic inclusion content of the metal was continually monitored by a newly developed light reflectance technique. In addition, chemistry was checked and adjusted to bring the metal into ASTM chemistry specifications. Analysis of the refining operation with respect to cleanliness showed that modifications to the argon gas distribution were necessary. After the necessary modifications were implemented, metal refining efficiency increased. The refined alloy was cast into 11 kg (25 lb.) ingots that were subsequently remelted at Contech's production facility. Parts were produced under the same conditions used for “virgin” metal, and the metal quality was again assessed with the light reflectance technique.

Increased requirements for crash energy management in automotive interiors have led to increased application of magnesium alloy AM50A. Successful integration of this new alloy with hot chamber diecasting process technology requires substantial adjustment and attention to processes and practices. This paper details the conversion of magnesium AZ91D steering column diecastings to high ductility structural alloy. Description is given of the changes made to foundry practices, casting parameters, process compliance monitoring, and hot end component management. The resulting improvements allow production of components comparable to the traditional alloy in manufacturing process demands while offering improved ductility and impact strength.