Development and manufacturing of aluminium low carbon footprint alloys

The utilisation of EN AB 42100 secondary alloys, i.e. AlSi7Mg0,3 alloys containing a high quantity of pre- and post-consumer material, have been tested in the low pressure die casting process for car wheels. Throughout the years different batches with secondary alloys in various ways and mixtures have been cast for two of the main OEMs, AUDI and BMW. This edged in the mass production of one AUDI part number. Such batches underwent a full metallurgical and technological validation proving that mechanical properties (Rp0,2, Rm, A% and hardness) of wheels cast with secondary alloys are comparable to the same part numbers produced with primary ones, despite the chemical composition showing slightly higher Fe, Cu, Mn and Zn content. All technological tests (rotary bending fatigue, 13° impact test, Radialschlag test, ZWARP test and paint tests) showed also good results in line with the validation done on parts made with primary alloys. This activity proved that the utilisation of aluminium alloys with high recycling rate is technically feasible.