Effects of cold deformations on strength and ductility of extruded Al-Cu-Mg-Si alloy

To improve strength and ductility, a series of experiments were designed and carried out to systematically and quantitatively analyze extruded Al-Cu-Mg-Si alloy without cold deformation (E0%) and with 4% cold stretching/ compression (ET4%/EC4%) prior to artificial ageing. The main aim is to investigate the different effects of cold stretching and compression on strength and ductility of extruded alloy. Compared to E0%, the EC4% alloy had finer phase 0, higher dislocation density, larger contact angle of Cu-rich phases so that had higher strength and lower ductility. Compared to EC4% alloy, the ET4% alloy had more proportion of phase 0 ', smaller contact angle of Cu-rich phases, which made ET4% alloy higher strength and higher ductility.