Influence of Chemical Composition and Process Parameters on Mechanical Properties and Formability of AlMgSi-Sheets for Automotive Application

摘要

The heat treatable AlMgSi-alloys of the 6xxx-series are widelyused for automotive sheet applications due to their goodcombination of strength and formability. Magnesium and siliconare the main alloying elements in this group forming the agehardeningphase Mg2Si. Moreover intentional addition of copper,manganese and also impurities (for example iron) can have asignificant influence on the mechanical properties and on theforming behavior of automotive body sheets. Beside the chemicalcomposition also thermo-mechanical process parameters can leadto changes in material properties. The purpose of this work is toinvestigate the influence of alloying elements and processparameters on (I) strength and (II) ductility in temper T4 and afterthe typical paint bake cycle at 185°C/20min. Furthermore (III) theformability of different AlMgSi-alloys is studied with bendingtests, cross-die tests, hole expansion tests and FLC-analysis.