The effect of preheating on the formability of an Al-Fe-Si alloy sheet

The present study examines the effect of preheating of cast material on the mechanical properties and formability of an Al-Fe-Si alloy sheet. The stretch formability of sheets has been characterized in terms of limit strains in forming limit diagrams (FLDs). Both conditions developed good combinations of strength and formability, giving forming limits in biaxial stretching comparable to those of commercial purity aluminum. Strain hardening, strain-rate hardening and surface roughening, which is developed during the plastic deformation of the material are found to be the key parameters. It appears that strain hardening and strain-rate hardening are the dominant factors at low annealing temperatures, while surface roughening is more important in the homogenized materials annealed at high temperatures.