Quench Sensitivity of Automotive Extrusion Alloys

Nick C. Parson¹, Jean-François Béland² and Jerome Fourmann³

¹Rio Tinto Aluminium, Kingston, Ontario, Canada
²National Research Council Canada, Saguenay, Québec, Canada
³Rio Tinto Aluminium, Chicago, Illinois, USA

Used with permission from the Proceedings of the Thirteenth International Aluminum Extrusion Technology Seminar (ET ’24), published by the Extrusion Technology for Aluminum Profiles Foundation and Aluminum Extruders Council

Abstract. Al-Mg-Si extrusions are widely used in automotive structures and crash management systems. In terms of material properties, a high yield strength is desirable for downgauging combined with superior ductility to accommodate plastic deformation associated with part forming, mechanical joining and crash with minimal cracking. The role of press quench is well recognised and water spray quenching is typically applied. The authors previously established a preferred minimum quench rate of 50°C/sec. However, the size and complexity of recent profile designs, e.g., for battery enclosures, can result in excessive distortion at high quench rates. It is therefore important to understand the material performance trade-offs with sub-optimal quenching. A test program was conducted using a purpose-built “quench simulator” to study the effect of quench rates in the forced air to spray regimes for a range of commonly used automotive alloys. Strength and ductility were quantified by tensile and bend testing.