Abnormal grain growth of 2196 Al-Cu-Li alloy weld seams during extrusion and heat treatment

The porthole die extrusion processes of 2196 Al-Cu-Li alloy were carried out at billet temperatures of 420–510 °C and ram speeds of 0.25–5.0 mm/s, then the extruded profiles were subjected to the solution and aging treatment. Abnormal grain growth (AGG) was observed along longitudinal weld of profiles during the extrusion and solution treatment. The fine equiaxed grains with Copper orientation were formed in the welding area when extruded at low...