Effect of Scandium addition on evolution of microstructure, texture and mechanical properties of thermo-mechanically processed Al-Li alloy AA2195

In the present study, influence of Scandium (Sc) content (0.025 and 0.25 wt%) on microstructure, texture and mechanical properties of a thermo-mechanically processed AA2195 alloy has been investigated. Addition of Sc to AA2195 alloy results in grain refinement and enhanced precipitation kinetics. TEM analysis revealed the presence of Al3(Sc,Zr) dispersoids in the Sc containing AA2195 alloys. Solution treatment and peak aging of the Sc containing alloys revealed partially recrystallized microstructure. Texture of Sc containing alloys displayed weaker Brass component compared to the Sc free material. A clear improvement in hardness and strength was observed which could be attributed to grain refinement as well as the presence of fine Al3(Sc,Zr) dispersoids. Ductility decreased slightly on Sc addition and there was an associated change in fracture mode as a result of Sc addition.