The influence of 0.1% Sc addition on the microstructure and texture development in Al-Zn-Mg-Cu-Zr alloys

In this study, the microstructure and the texture development in Al-Zn-Mg-Cu-Zr alloys with/without 0.1%Sc has been investigated after extrusion, cold rolling, and aging treatment. After aging treatment, in Al alloy without Sc recrystallized equiaxed grains are obtained, while in Al alloy with Sc fine grains with an average size of 0.1 similar to 0.3 mu m are obtained. After cold rolling, in case of the sample from the cross section (CS) to which Sc was added, texture with {112}< 111 >(Cu) + weak {123}< 634 >(S) component was developed while in case of the sample from longitudinal section (LS) to which Sc was added, texture with strong beta-fiber + {110}< 001 >(Goss) components was developed. In case of CS and LS without Sc, texture of beta-fiber was developed. After solid solution treatment and aging treatment, Al alloys (LS and CS) with Sc had rolling texture while Al alloys without Sc had random texture. The role of these differently developed textures in the plastic behavior, such as the normal anisotropy r-value (the plastic strain ratio) and planar anisotropy Delta r-values are discussed.