Experimental investigations on energy absorption capacity of selected Al–Si–Mg casting alloys

Abstract

Three hypoeutectic Fe containing Al–Si–Mg alloys for casting crash relevant automotive components are experimentally investigated. The comparatively short heat treatments include solutionising at 540°C for 5 min or at 465°C for 60 min respectively, compressed air quenching and artificial aging at 223°C for 120 min. Characteristic mechanical parameters are determined by tensile, plate bending and Charpy pendulum impact tests. Intermetallic phases are identified by scanning electron and by light microscopy. The results show that increasing the Mg content promotes the precipitation of Mg₂Si particles, which enhance the strength. Increasing the Fe content promotes the formation of intermetallic Fe bearing particles which reduce the energy absorption capacity and the ductility. Increasing the Si content has the similar effect, since the volume fraction of the eutectic phase and the size of the intermetallic particles increase.

Keywords:

• Al–Si–Mg casting alloys
• Energy absorption
• Mechanical properties
• Heat treatment

Acknowledgements

The authors would like to thank the Austrian Research Promotion Agency, the Federal Ministry for Transport, Innovation and Technology and the State of Upper Austria for supporting this work within the framework of the COMET research program.