Effect of Si Content on Deformation Behavior of DC Cast Al-Si Alloys

The deformation behavior of DC cast Al-2Si and Al-15Si alloys have been studied by means of compression test at temperature range of 300-500°C and strain rate range of 0.01-5 s-1. The results show that the flow stress of the Al-Si alloys increases with decreasing compression temperature and increasing strain rate. The flow curves determined from the compression tests exhibit that the deformation of the materials is controlled by two competing mechanisms: strain hardening and flow softening. Higher silicon content in the alloys also leads to higher flow stress during deformation and tend to show more significant flow softening. Particle damage during the deformation may have an influence on the flow curves of the alloys.