Effect of intermediate annealing time on microstructure, texture and mechanical properties of Al-Mg-Si-Cu alloy

The effect of intermediate annealing time on the microstructure, texture and mechanical properties of Al-Mg-Si-Cu alloys was studied by mechanical properties, microstructure and texture characterization in the present study. The results show that the intermediate annealing time has some influence on the microstructure, recrystallization texture, and final mechanical properties. After the pre-aging treatment and natural aging treatment (T4P treatment), in contrast to the sheet with short intermediate annealing time, the sheet with long intermediate annealing time possesses higher plastic strain ratio r value. Strength has no positive correlation with annealing time, and when applying the annealing time of 16 h, the strength is highest. Before solution treatment, the sheet with long intermediate annealing time has more particles with a larger average size, compared with the sheet with short intermediate annealing time. After solution treatment, they possess the similar recrystallization equiaxed grain structure and recrystallization texture. The sheet with short intermediate annealing time is comprised of CubeND {001} 〈310〉, Goss {110}〈001〉 and P {011}〈122〉 orientations, while the sheet with long intermediate annealing time possesses weak texture including CubeND {001}〈310〉, Goss {110}〈001〉 and {015}〈751〉 orientations. Finally, a particle dissolution model during solution treatment is proposed to explain the variation of strength with annealing time.